请问move forward可以换成move forth吗?

可以.
Move forward to the jungle.
Move forth to the jungle.

forward, forth 同是[介词]

move forward
[mu:v ˈfɔ:wəd] 美 [muv ˈfɔrwəd]
前进
1.Move forward to the front of the train.
前走到列车的前面.
2.In the past,the work in the factory could not move forward for lack of necessary rules and regulations.
过去由于规章制度不健全,这个厂的工作老是上不去.
3.He's hoping to forward his career by this move.
他正希望通过这一举动来促进他的事业.
4.After this,we are equipped to move forward.
在这之后,我们就足以继续向前讨论了.
5.Given this pressing situation,we must move forward,or we will fall behind.
形势逼人,不进则退.