A multi-cylinder Stirling engine transmission system comprises single-cylinder Stirling engine bodies and a transmission shaft. The transmission shaft is provided with a crank throw. Each single-cylinder Stirling engine body comprises a piston, wherein the piston is in power connection with the crank throw through a connecting rod, and a power unit is formed. The four power units are arranged, a virtual center line perpendicular to the axis of the transmission shaft is arranged, and the included angle is formed by the four power units relative to the virtual center line. The multi-cylinder Stirling engine transmission system has the following beneficial effects that the usage requirement of a multi-cylinder Stirling engine can be met; the structure is compact, output power is uniform, thebalance performance is better, bearing loads are small, and motion reliability is high; a power transmission gear mechanism is eliminated, accordingly, exciting force caused by gear transmission is eliminated, and vibration and noise are further lowered; and meanwhile, mechanical work consumption is reduced, the single-machine power of the Stirling engine can be properly improved, and power density is further improved.