The invention discloses a double-cylinder rotating compressor which comprises a shell body, a motor, an upper
flange, an upper air cylinder, a
crank shaft, an upper running
pulley, a partition plate, a lower running
pulley, a lower air cylinder and a lower
flange. The
radius of a cylinder matched segment of the portion in which the
crank shaft is matched with an inner hole of the partition plate is larger than biggest eccentric radiuses of an upper eccentric portion and a lower eccentric portion of the
crank shaft, the cylinder matched segment of the crank shaft is matched with the inner hole of the partition plate in a sliding mode to form an auxiliary bearing of the compressor, the bottom end face of the lower eccentric portion of the crank shaft is arranged in an alignment mode corresponding to the bottom end face of the lower air cylinder, and the corresponding lower
flange is a plane plate. The lower flange enables the lower running
pulley and the lower eccentric portion of the crank shaft to be blocked in the lower air cylinder in an alignment mode, an original short shaft of the crank shaft is removed, the height of the shell body is reduced, frozen oil filling injection amount is reduced, and
power consumption of the compressor is reduced. The invention further discloses an eccentric assembling method of the double-cylinder rotating compressor, a combined centering assembling mode from top to bottom is adopted by the method, and the problem that coaxiality difference of the long shaft and the short shaft of the existing crank brings problem for a gap of the lower cylinder is solved.