The invention relates to a dynamic quality detection method for whole 
assembly of automobile products. The method comprises the following steps: N 
assembly welding or bolt junction points between the 
chassis component and the automobile body component of the automobile product are selected as standard detection points, and the dynamic rigidity of the 
assembly coupling junction interface where the N detection points are located form a 
complex matrix (Kd); excitation test is performed on the positions of the standard detection points, the 
matrix element of a 
frequency response function of test signals is recorded, and a standard value (Kd)0 is calculated; excitation test is performed on the automobile products of the same 
model number, the evaluation index value (Kd)n of the nth detected automobile product is calculated, the absolute value of difference value between the evaluation index value (Kd)n and the standard value (Kd)0 is calculated according to the formula that 
delta = |(Kd)n - (Kd)0 |; and if the ith 
diagonal entry magnitude of the absolute value is smaller than a reference value, the dynamic quality of the ith 
welding of the automobile product is regarded as excellent, otherwise, the dynamic quality of the ith 
welding of the automobile product is regarded as poor or moderate-level. Through the dynamic quality detection method, the dynamic quality of the 
machine assembly of the automobile products can be directly detected and evaluated.