With the development of technology in the power field gradually becoming digital and automated, technologies such as cloud computing and big data are gradually applied to sense and control the power grid. However, accurate sensing and measurement of the grid state is the main technical basis for data analysis and automated operation and maintenance. Therefore, this paper proposes a multi-point synchronous phase measurement method based on non-contact microsensors to address the shortcomings of existing grid sensors in terms of sensing accuracy and timeliness. The method solves the synchronous phase measurement problem of grid PMUs by deploying non-contact TMR sensors to achieve single-axis current measurement. And based on this, the multi-point synchronous phase measurement method is improved and designed to solve the theoretical accuracy error caused by wire eccentricity. Meanwhile, it is combined with the dynamic phase measurement method to characterize the synchronous phase change and represent the dynamic characteristics of the grid signal more accurately. The simulation results of the experimental platform show that the measurement error size of the multi-point synchronous phase measurement method is within 4%. Moreover, its phase angle measurement error is less than 0.25 degrees, which can realize the synchronous phase measurement of non-contact sensors. It not only reduces the measurement error caused by the environment, but also makes the measurement more convenient and faster, promotes the digital development of the power grid, and provides great convenience for the fault detection and operation and maintenance of power equipment.