Provided is a channel access method. The method includes: after a radio frame is received, determining that the radio frame is an overlapping basic service set (OBSS) radio frame; determining that the OBSS radio frame is a radio frame of a specified type or determining whether the OBSS radio frame carries specific spatial multiplexing instruction information; updating a local network allocation vector according to duration information carried in the OBSS radio frame; and performing channel access according to the local network allocation vector. Provided are a channel access device and a storage medium.