The invention relates to a high-gain low-noise frequency mixer which comprises a switch level module and an active load module. The common-mode voltage output end of the switch level module is connected with a common-mode feedback module which is used for stabilizing the common-mode voltage, the output end of the common-mode feedback module is connected with the active load module, the output end of the active load module is connected with the switch level module and a dual-capacitor cross coupled transconductance module, the switch level module is also connected with a tail current source module, and the switch level module uses an active Gilbert double-balance structure. According to the technical scheme, the equivalent transconductance value is effectively improved by using a gate drive and substrate drive dual-capacitor cross coupling manner on the basis of a traditional folded structure transconductance; and on the premise that the power consumption is not increase, the noise coefficient of the frequency mixer is reduced, and the gain of the frequency mixer is improved. Use of the active load module improves the conversion gain of the frequency mixer, and the common-mode feedback module is used to stabilize the common-mode voltage of the output point and improve the linearity of the frequency mixer.