A circuit design of down conversion module in Ku-band is introduced. The circuit is divided into upper and lower cavities to solve the wiring crossover problem of local oscillator signals in multi-channel frequency conversion design. The crosstalk of high and low frequency signals is suppressed by the connection of coaxial cable of intermediate frequency, with improving the harmonic suppression of the circuit. The test results show that the gain of the module is 46 dB，the band of IF is 15 MHz and 30 MHz, the suppression of the specific frequency is more than 60 dBc, and the sensitivity is 80 dB, indicating that the module meets the requirements.