How to go by subway from Beijing Agriculture Exhibition Centre to Muxi Yuan?

You can take subway line 10 from the exhibition center to Guomao, transforming to subway line 2 to Dongdan and then take subway line 5 to Liujiayao. Then catch a taxi to Muxiyuan.
Well, I think you can also take bus Yntong 107 from the exhibition center and get off at Majiabao Beikou, then walk about 3 minutes to Muxiyuan.