Uneven load distribution of bolt group is one of the important reasons for vibration and even damage of large equipment.In engineering,the bolt joint points are often subjected to complex time-varying low-speed heavy loads,and the bolt group is easy to break due to uneven load distribution,which affects the stability of equipment operation.In order to study the stress of the bolt group under different bolt distribution,the mechanical model of multi-bolt connection was established to analyze the bolt load distribution.On this basis,a load calculation method of multi-bolt connection was proposed considering the complex structure of the connection.Experimental study and finite element analysis were designed and carried out,and the accuracy of the calculation method was verified by comparing the results.Based on the proposed theoretical calculation method,the distribution law of bolt shear stress under load was given,and the shear stress distribution characteristics of uniform distribution model and non-uniform distribution model of bolts were compared.It is found that the uniformity of load distribution of non-uniform bolt distribution is better than that of uniform bolt distribution.