The invention provides a gas compressor structure of a double-gas-inflow turbocharger under a share diffuser. The structure comprises a former-stage gas inflow gas compressor volute, a later-stage gas inflow water-drop-shaped gas compressor volute and a diffuser passageway. The later-stage gas inflow water-drop-shaped gas compressor volute and the diffuser passageway are fixed to form a later-stage gas inflow combination, and the former-stage gas inflow gas compressor volute is fixedly installed on the later-stage gas inflow combination in a linked manner; the diffuser passageway is arranged between the former-stage gas inflow gas compressor volute and the later-stage gas inflow water-drop-shaped gas compressor volute. The gas compressor structure of the double-gas-inflow turbocharger under the share diffuser has the following beneficial effects that the requirements of the double-gas-inflow share diffuser are met, the design difficulty of the shell structure is lowered, and the machining accuracy of the shell structure is improved.