Schottky mixer is the key component of terahertz receiving system. Compared with the receiver based on SIS (superconductor-insulator-superconductor) mixer and HEB (hot-electron bolometer) mixer, the terahertz receiver system constructed on the basis of Schottky diode mixer does not rely on low-temperature accessory equipment, and it has the advantages of low cost, light weight, small volume and low power consumption. At present, the structure of terahertz receiver front-end based on Schottky diode mixer is relatively complex. To solve the problems of complex structure, low integration and high loss of terahertz receiver front-end, a 288-318 GHz sub-harmonic mixer based on Schottky diode and its local oscillation channel is proposed. Accordingly, a terahertz receiver system based on this mixer is constructed. The terahertz receiver’s local oscillation channel consists of a 75 GHz sextupler, a power amplifier integrated module and a 150 GHz frequency doubler. The integrated design of the local oscillator channel makes the receiver integration greatly improved. The overall size of the integrated module is 20 mm×20 mm×43 mm. The final test of the receiver shows that: in the bandwidth of 288-318 GHz, the double sideband conversion loss of the receiver is 5.8-9.4 dB, and the noise temperature is 1 055-1 722 K, which has good RF performance.