Free-range pig high-efficiency monitoring system and method

The invention provides an efficient monitoring system and method for free-range pigs, and the system comprises a first monitoring device which is arranged for a leading pig in each pig herd, and the first monitoring device comprises a first controller, and a miniature projector, a positioning module, an orientation sensor and a first communication module which are connected with the first controller; the system further comprises a remote server. The remote server sends a loop instruction to the first controller corresponding to the leading pig; after receiving the loop instruction, the first controller sends first identification information of the first controller and leading pig positioning information provided by a positioning module of the first controller to a remote server; the remote server sends azimuth information of the target pigsty relative to the leading pig to the first controller according to the first identification information; the first controller controls the miniature projector to block wal