The mathematical model of “pile effect” was built in the process of gas hydrate sampling coring and the implicit analytical solution for the sample height is presented by analytical analysis. The influences of the sampling tube diameter and the friction coefficient between the sample and the sampling tube were analyzed. Parametric analysis shows that the inherent friction angle and cohesion of the target layer have great influence on the sample height. The sampling depth in the target layer has unapparent influence on the sampling rate.