Charging over-temperature protection method and system for alternating current charging pile

The invention provides a charging over-temperature protection method and system for an alternating current charging pile in the technical field of alternating current charging piles. The method comprises the steps that S10, an MCU of the alternating current charging pile sets a first temperature lower limit value, a first temperature upper limit value, a first over-temperature back-fork value, a second temperature lower limit value, a second temperature upper limit value and a second over-temperature back-fork value; s20, in the process that the alternating current charging pile charges the electric vehicle through the charging gun, the MCU detects the environment temperature value in real time through the environment temperature detection module, and detects the phase line temperature value of each phase line in real time through the phase line temperature detection module; s30, the MCU carries out environment over-temperature protection according to the first temperature lower limit value, the first tempera