An implementation method for completely recording spacecraft real-time telemetry data comprises the steps that (1) a telemetry download period of a CTU is set to be the download time of four-frame telemetry information, meanwhile, the CTU is set to pass through two time slices to store the data, and two-frame telemetry information is stored in each time slice; (2) a solid-state memory is arranged and used for storing the dumped data of the CTU and the CTU is communicated with the solid-state memory through a 1553B bus; (3) telemetry information is collected by the CTU in real time and stored in an SRAM; (4) in each telemetry download period, the downloaded telemetry information is judged by the CTU, special data sections are stored during a data download period with the section sequences between 63 and 103, real-time telemetry data are stored during a data download period with the section sequences between 1 and 62, data sections with the section sequences between 104 and 127 are stored during a data download period with the section sequence of 0 and the section sequences between 63 and 127, and all the data which need to be stored are stored in the solid-state memory by the CTU through the 1553B bus.