Terahertz waves occupy a unique position in the electromagnetic spectrum, characterized by high frequency, high bandwidth, and high penetration, which hold broad application prospects in fields such as communication, radar, imaging, sensing, and security inspection. Frequency converters like frequency multipliers and mixers are key components of solid-state terahertz systems. Schottky diodes boast low parasitic parameters, simple fabrication processes, and ease of integration, with their operating frequencies covering the entire terahertz band. Frequency conversion devices based on Schottky diodes, featuring room-temperature operation, broad bandwidth, electronic tunability, low phase noise, and high sensitivity, have become the mainstream devices in terahertz transceiver links. This article reviews the recent developments in Schottky diode technology, including its structure and fabrication methods. Additionally, it introduces the current state of frequency multipliers and mixers based on Schottky diodes and discusses future development trends.