The invention provides an online data migration method in support of a heterogeneous timing sequence database, solving the defects of incapability of crossing timing sequence database types, incapability of crossing networks and long application offline time of methods for migrating data through data recovery. The method includes deploying a target database X-DB, determining a time cutoff point, deploying a multichannel data agent, connecting the multichannel data agent to the target database X-DB, setting low priority and temporary disability, storing timing sequence data into a source database and an X-DB operation log, staring a source data and historical data pump to extract a data package from a required starting time to the time cutoff point, compressing and transmitting the historical data package and the operation log, performing historical data recovery by an X-DB data pickup device, performing log registration, creating a log stop identification after all piled logs are transmitted and recovered, interrupting the source database, starting an X-DB node, stopping log creation by the multichannel data agent, and selecting the X-DB database according to configuration rules to switch the target database automatically.