The invention relates to a method for realizing four-channel serial communication of an SDRAM (Synchronous Dynamic Random Access Memory). The method comprises the steps of: transmitting command signals through one channel, and decoding command signals received from a serial channel D0 through a command control logic unit and recognizing the commands, wherein commands for serial four-channel SDRAMinclude a read operation command, a write operation command and an initialized configuration command; after the command control logic unit recognizes the initialized command, outputting a signal for configuring a PLL (Phase Locked Loop) and refreshing a counter, executing the configuring operations of configuring the PLL and refreshing the counter; after the command control logic unit recognizes the read and write commands, analyzing a received address signal to generate a column address, a row address and a BANK signal and sending the column address, the row address and the BANK signal to a column address latch decoder, a row address latch decoder and a BANK control logic; and then transmitting data signals, wherein the transmission of the data signals is controlled by a read-write register. The method changes the parallel communication mode of the SDRAM to the serial communication and realizes the four-channel serial communication function of the SDRAM.