The invention relates to a ratchet wheel angle monitoring device for an overhead contact mesh system. The ratchet wheel angle monitoring device comprises a shell body mounted on a ratchet compensation bracket, an angle sensor and an anti electromagnetic interference circuit are arranged inside the shell body, wherein the angle sensor adopts an accelerometer; the angle sensor is connected and communicated with an aggregator mounted on a support of a compensation lower anchor through a soft cable. According to the ratchet wheel angle monitoring device for the overhead contact mesh system, accurate measurement of ratchet angle data can be achieved, collected data can be transmitted to the aggregator, uniform analysis of the data by an operation management organization is facilitated, the safety hidden trouble of the overhead contact mesh system can be discovered in time and eliminated, and the reliability and safety of a traction power supply system are greatly improved. The product is simple in structure and easy to use, the technical effects are remarkable, the device can be widely used in occasions of online monitoring product design of a ratchet wheel compensation lower anchor device of the overhead contact mesh, and the requirements for the field environment work of the overhead contact mesh system are met.