The boom is one of main load bearing parts for the excavator operation; accordingly, it is very important to make the strength calculation. Considering the excavator boom is of complicated working condition and difficult stress analysis, based on the expression of parts of the excavator working device concerning length parameters of the cylinder, establish the full parameterization model in the MSC.adams, so as to make the secondary development process, automatically achieve the force analysis and calculation of all-poses, and process and save hinged forces under all-poses. In addition to the above, by establishing the finite element parameterization model, invoke the macro command to modify all hinged forces, so as to calculate the max. equivalent stress of the boom under all-poses. The calculation result shows that, the boom can meet the strength requirements under all-poses.