This application provides a multichannel data transmission method performed at a proxy server when communicating with a mobile terminal and a target service server. The multichannel data transmission method includes: receiving, from the mobile terminal, a plurality of uplink data packets in parallel through a plurality of channels, parsing the plurality of uplink data packets to obtain a plurality of target service data packets and a plurality of uplink packet headers, performing deduplication processing on the plurality of target service data packets according to the plurality of uplink packet headers, and transmitting the target service data packets reserved after the deduplication processing to the target service server, each uplink packet headers including a packet sequence number of each uplink data packet. The uplink data packets can be transmitted in parallel through the plurality of channels, and reliable and effective transmission of target service data packets is implemented through deduplication processing.