The invention provides a physical simulation analysis method of a Bohai bay basin formation mechanism. The method comprises steps of step S1, based on basic shape characteristics of the Bohai bay basin, designing a construction physical model with a similar proportion; step S2, based on stratigraphic distribution conditions and fracture system characteristics of Ek-Es4 deposition periods of the Bohai bay basin, using a northwest-southeastward extension mode; step S3. Based on the stratigraphic distribution conditions and fracture system characteristics of Es3-Ed deposition periods of the Bohaibay basin, using near south-northward extension mode; step S4, based on the stratigraphic distribution conditions and fracture system characteristics of Ng-Nm deposition periods of the Bohai bay basin, using a counter-clockwise rotation mode; and step S5, explaining a plane result graph and a profile result graph obtained in the above experiment, and carrying out comparison and analysis on the actual tectonic framework characteristics, the stratigraphic distribution characteristics and the fracture system characteristics of the Bohai bay basin. According to the invention, the model construction mode is simple, the simulation mode is easy to achieve, the simulation result is highly accurate and the repeatability is high.