A downlink channel transmission method, and a downlink channel transmission device are provided. The downlink channel transmission method includes: determining a transmission parameter of a physical downlink shared channel (PDSCH), where the transmission parameter includes: a number of times N of repetition transmission and a repetition transmission mode, where N is greater than or equal to 1 and is a positive integer; and transmitting first downlink data carried on the PDSCH, according to the transmission parameter.