The invention discloses a multi-network converged electricity information collection system and an optimal communication network selection method. The system comprises a communication interface server, a heterogeneous network convergence resource management unit, a WiMAX access gateway, an optical switch and a wireless public network access gateway, wherein the communication interface server receives data which are collected by the heterogeneous network convergence resource management unit and uploaded in different communication modes, and the data are processed and uploaded to a control center; the heterogeneous network convergence resource management unit receives data uploaded by the WiMAX access gateway, the optical switch and the wireless public network access gateway; the WiMAX access gateway receives data uploaded by an electricity information collection terminal through a WiMAX network base station; the optical switch receives data uploaded by the electricity information collection terminal through an optical fiber combiner; the wireless public network access gateway receives data uploaded by the electricity information collection terminal through the WiMAX network base station, an LTE (long term evolution) base station, a TD-SCDMA (time division-synchronous code division multiple access) network base station or a GPRS (general packet radio service) network base station. According to the multi-network converged communication system, the optimal communication access network under different specific scenes is selected in consideration of reliability and timeliness.