An eccentric gear groove-controlled synchronous artificial respiration and cardiac compression operating instrument is composed of an air circulating cabinet, an air circulating piston and a set of operating coordinators.A fresh air circulating room and an exhaust air circulating room are arranged in the air circulating cabinet, external cardiac compression can be performed on a patient while fresh air is fed to the patient or exhaust air in the body of the patient is exhausted by pressing or pulling up the air circulating piston through an eccentric gear, and therefore rescuing effect can be improved; through changes of the combination position of the eccentric gear and an operating shaft, the instrument can adapt to the patients with different vital capacities.