Measurement-device-independent quantum key distribution (MDI-QKD) can remove all the side-channel attacks and significantly improve the secure transmission distance. However, the key generation rate is relatively low when taking finite-key-size effect into consideration. In this manuscript, we adopt the latest four-intensity decoy-state scheme combining the heralded pair-coherent sources to study the performance of the MDI-QKD. Moreover, through utilizing joint constraints and collective error estimation techniques, we can obviously improve the performance of practical MDI-QKD systems compared with those using weak coherent sources or heralded single-photon sources.