The invention relates to a method for locating a top dead center of a six cylinder engine. The method includes the steps of installing an acceleration vibration sensor on the six cylinder engine and connecting a computer through a vibration signal collecting instrument, collecting vibration response time domain signals of six cylinders, changing the vibration response time domain signals to complex signals, obtaining combustion impact response characteristic parameters of the six cylinders, listing digital quantization matrixes, setting the combustion impact response characteristic parameters as XA, XB, XC, XD, XE and XF respectively, listing each of the matrixes corresponding to the combustion impact response characteristic parameters of the working cylinders, and multiplying and summing elements of each of the matrixes correspondingly and comparing to obtain the XA which is among maximum values and corresponds to an engine working cylinder which the top dead center corresponds to as well. By means of the method for locating the top dead center of the six cylinder engine, the accurate location of the engine top dead center is achieved, the identifying speed of an engine fault cylinder is improved, the diagnosing time of the engine fault cylinder is shortened, the method is simple, the operation is easy, and the maintenance of the engine is facilitated.