Princess Agents (2017)

Similarities:
-Princes falling in love with a maid
-Rebellion
-inter competition between all the princes
-lover triangle
-The characters Wang Wook (Moon Lovers) and Yan Xun (Princess Agents) have a very similar goal, but end up hurting the one they love

Princess Agent has defiantly more danger and action pact.
-secret organizations

Moon Lovers: Scarlet Heart Ryeo focuses more on the romance and relationships between the Female main lead and the Princes.

They are similar because both FL know how to fight. Also, from one of Yang Mi's posters, she's in a similar position to Zhao Liying because she is also holding a bow and arrow in shooting position.

I've been jumping around (skipping scenes in) Princess Agents a lot so sorry if this is completely a completely off recommendation..
but some of the character personalities are very similar.

XE is like QingSuo- others controlling their life, losing memory of their past, stuck in love triangle, stuck with someone who they kinda hate but end up loving

Yu WenYue similar to Yu WenYong (yeah even their names are similar)- royalty, cold on the outside and warm on the inside, always mistaken by their love

Quite similar genre type of drama and storyline. Involved politics, war, fighting for the throne, and from sweet to bitter to sour to regretted love affairs.

both dramas FL is smart enough to deal with political issues and warrior/fighter when needed , she is center of attraction of all ML in not only romance for strategies issue also , she faces amenesia

princess agent is by far better than anything else

Both have strong female leads who are martial arts.

Multiple men fawning over the female lead.

Both female do not agree with their status.

a strong independent woman who knows very well fight that has nothing to envy men. Indeed sword shield arrow nothing has any secret for this one
  if you are looking for a woman with a strong character, this is what you need

In both series there is:
* a woman from another era
* who doesn't remember who she is
* and has never been in love before.
The romance has:
* a love triangle
* men who are fighting on opposite sites
* wuxia elements
The music in the background:
is used in both series.

Similar themes. Female leads saves the world in the end for revenge. If you want to watch a drama with a female lead who isn't so naive, Princess Agents is recommended. Though both endings were not satisfying, but at least Princess Agents plot had more development.
Warning: That drama is also as twisted and graphic as this one.

Although I almost didn't watch "Princess Agents" because the beginning was so shocking, it ended up being one of my very favorite Asian dramas. It has every element of an exciting, entertaining, edge-of-your-seat drama. I have watched it several times and recommend it to all my friends. The actors are amazing in this drama and I know you'll come back for more--the female lead is one of the strongest I've seen and the humor scenes are hilarious. I must admit there is a cliff hanger at the end and no sequel in sight so far, which breaks my heart, but it is still a must-watch in my book! Totally worth it. I rated it 10/10.

Firstly, both dramas share the same female lead. They are also based on Historical Era. Just like Princess Agents, The Journey Of Flower also has the occasionally plot to frame the main lead. Although the plots are completely different in a sense that it isn't about slavery or time travel, they are still excellent Chinese dramas. Ps. I wrote this because I'm reminded of how playful Zhao Zanilia is in The Journey Of Flower, she is a great actor. Also I may sound weird but,.... I hope she finds a partner soon. Ps,s I'm saying this because it doesn't say she has a spouse on Google if you search up her name. Don't quote me!!!, Ps.S.S, I'm loving this drama despite the fact that it's such a distraction while I'm doing homework.