The invention discloses an operation repositor having an external endoscope and being used for left displacement of abomasum of cows. The operation repository comprises a high-pressure air source, a suture line, a reset needle, and a propelling device. The propelling device is externally provided with a portable endoscope. The outer edge of the propelling device is smooth. The propelling device comprises a propelling unit, an air supply unit which is on the tail part of the propelling unit and is connected with the propelling unit, and a needle storage bin which can hold the reset needle. Theair supply unit comprises a gas pipe and a connector. The head of the needle storage bin is provided with a needle outlet hole for the reset needle to pass through. The needle storage bin is providedwith a line leading groove on the needle outlet hole. The propelling unit comprises a main cylinder, an air cylinder, a piston, a piston rod, and a buffer cushion. The tail part of the air cylinder isout of the main cylinder and is connected with the connector of the air supply unit. The piston rod passes through a guide pipe which is arranged on the bottom of the main cylinder and enters the needle storage bin. The tail part of the reset needle is fixed on the head of the piston rod. The gas pipe is connected with the high-pressure air source. The gas pipe can be flexibly bended, and reducescompression on visceral organs, and reduces operation time.