Rapid replacement device and replacement method for carried agricultural machinery

The invention discloses a rapid replacement device and a replacement method for carried agricultural machinery. The rapid replacement device comprises an auxiliary frame, an agricultural machinery underframe and a telescopic leg; the auxiliary frame is installed on a rear frame of a tractor; the agricultural machinery is installed on the agricultural machinery underframe; when in use, the underframe equipped with the agricultural machinery is installed on the auxiliary frame which is fixed with the rear frame of the tractor together; the agricultural machinery can be smoothly installed only bylocking front and rear lock catches; when other agricultural machinery is replaced, the front and rear lock catches are only needed to be loosened, the agricultural machinery underframe and the agricultural machinery fixed on the agricultural machinery underframe can be integrally lifted through the adjustment of the telescopic leg, and the agricultural machinery can be smoothly replaced, and when other agricultural mach