The present invention provides a multi-focus swept source OCT (optical coherence tomography) focusing device and a method thereof and belongs to the optical imaging technological field. The device includes an electric lifter and a focusing mechanism; the electric lifter comprises a carrying table; a diaphragm and a fixing clip which is used for fixing a sample to be detected are arranged on the carrying stage; a converging lens is disposed above the carrying stage; a semi-reflecting and semi-transmitting lens is arranged above the converging lens; the focusing mechanism comprises a swept source and a first optical fiber coupler; the optical path of the first optical fiber coupler is connected with a reference optical path and a sample optical path; the reference optical path includes a first optical circulator, a first collimating lens, and a plane mirror; and the sample optical path includes an optical circulator and a polarization controller. According to the focusing device and method of the invention, coherent light is introduced to generate interference, and therefore, the automatic focusing of a distance from the sample to be detected and the focus of an optical system can beanalyzed, and focusing accuracy and speed can be effectively improved.