The invention discloses an animal activity monitoring system and an activity state recognition method based on a neural network. The animal activity monitoring system comprises an acquisition device and an intelligent terminal application, and the acquisition device acquires contact pressure, activity range and acceleration information of monitored animals and judges whether effective contact occurs or not according to the magnitude of the contact pressure; the intelligent terminal application receives effective animal data of the acquisition device and recognizes the effective animal data into the animal activity state. By means of the recognition method, based on a neural network model, a sample set can be trained and learned, and based on the trained model, the activity state of the animals can be recognized. By means of the system, animal activities can be automatically detected and remotely monitored in real time, manual detection or recording is not needed, and a lot of manpowercan be saved; by means of the method, the difference like the type, the age, the individual and the motion state of the animals can be eliminated, all monitored objects are truly customized, and the purpose of precisely and effectively detecting the activity range is achieved.