A high speed optical module, and in particular, a multi-channel, single-mode, parallel transmission optical module in the field of optical communication is disclosed. The optical module includes a chassis, a first transmitter optical subassembly (TOSA), a second transmitter optical subassembly (TOSA), a third transmitter optical subassembly (TOSA), a fourth transmitter optical subassembly (TOSA) and a MT fiber connector. The TOSA may be a TO-38 TOSA of a 10 G DFB chip or FP chip. With single-mode communication, the optical module provides a transmission distance over 10 kilometers. In addition, to make coupling single-mode fibers easier, a twelve-core MT fiber connector is employed, wherein four fiber connectors are respectively connected to LC standard fiber stubs and the outputs of the TOSAs accordingly. Thus, the optical module further provides high speed and long-distance transmission, large capacity, small volume, and light weight and can be broadly applied to high speed optical communications.