In order to monitor the condition of lubricating oil with multi-information simultaneously, a composite sensor based on quartz crystal microbalance (QCM) was developed, which can monitor the viscosity and wear particles of lubricating oil simultaneously, and a series of experiments on the stability of the sensor under different oil temperatures were carried out. The experimental results show that the sensor has high linear response and sensitivity to the change of lubricating oil viscosity and wear particle content, and can accurately measure lubricating oil viscosity and wear particle content, and is stable and reliable.