A data transmission method, applied to a terminal that uses a dual connection mode of non-standalone networking for data transmission, includes: monitoring a network signal quality in the dual connection mode of non-standalone networking, and monitoring a real-time data packet transmission rate of a data packet transmitted and received by the terminal; and adjusting, based on the network signal quality and the real-time data packet transmission rate, the dual connection mode of non-standalone networking, which includes turning off the dual connection mode of non-standalone networking or maintaining the dual connection mode of non-standalone networking. Automatic and dynamic switching between EN-DC dual connection and single 4G network connection can be realized, without manually switching networks by users, such that effective transmission and reception of terminal data packets is ensured, and increase in power consumption caused by always relying on the EN-DC dual connection is avoid.