Underground load dynamic balancing method for tractor

The invention discloses an underground load dynamic balancing method for a tractor. The method comprises the steps that the current working voltage U, the current working current I, the current working rotating speed N, the current PWM duty ratio d and the current underground tension f of a tractor motor are collected; an adjustment coefficient K2 = 9550 * U * I * K1/(100 * N * R) is calculated, K1 is the reduction ratio of the tractor, and R is the radius of a traction wheel of the tractor; when |delta f/f| is larger than 5%, a new PWM duty ratio d1 is calculated according to the formula d + (delta f/100K2), the tractor motor adjusts the working parameters of the motor according to the new PWM duty ratio d1, and delta f is the average value of the tension increment. The power output matched with the load is obtained by collecting measurement parameters, dynamically sensing the operation condition of the tractor and calculating a new PWM duty ratio, so that the loss of parts of the tractor is reduced, and the