The invention discloses a wind power plant ultrasonic wind speed monitoring method based on a single chip microcomputer. The method includes the following steps of opening an FPGA port used for sending a data transmission interrupt request to the single chip microcomputer, receiving ultrasonic flight time from ultrasonic probes according to a data transmission clock of an FPGA, obtaining wind speeds of the three pairs of the ultrasonic probes in the linear direction by calculating the flight time, obtaining the sonic speeds through calculation, obtaining the wind speeds, wind directions and temperatures in the three-dimensional directions through calculation, storing the data, judging whether user data for requesting interruption of the single chip microcomputer exist, returning to the second step if no interruption requests exist, analyzing an interruption command if an interruption request exists, calculating wind power plant information according to the interruption command, and sending the data to an upper computer through an RS485 bus interface. The method has the advantages that the wind speed of a wind power plant can be accurately predicted, and accordingly electricity generating capacity can be accurately predicted, a power grid can be reasonably dispatched, and safety of the power grid is guaranteed.