Abstract: To solve the problem of analyzing and synthesizing multiple uncertainty sources of coordinate measuring machines (CMMs), the 21-item geometric motion error separation method of CMMs based on spherical column and Monte Carlo simulation algorithm is used to realize the task-oriented measurement uncertainty evaluation of CMMs, and the traceability service system of CMMs based on “Internet+” is established. The provincial and municipal metrology institutes act as traceability network nodes to assist in data collection, including error parameters, environmental parameters, and instrument parameters. When the user needs to perform task-specific measurements, the measurement strategy is sent to the National Institute of Metrology and the results are fed back to the user via the network. This traceability network reduces the length of the traceability chain to a certain extent and realizes the flattening of measurement.