In order to solve the problems of low estimation accuracy and long estimation time of traditional construction project cost estimation methods, a new fast estimation method of green construction project cost based on support vector regression machine is proposed in this paper. Firstly, according to the principle of support vector regression machine, the nonlinear classification function of green building cost data is constructed to complete the classification of cost data. Secondly, based on the classification results, the principal components of the sample data series of cost estimation are calculated, and the constraint parameters of cost estimation are constructed. Finally, according to the relationship between green building construction cycle and overall project cost, a fast estimation model of green building project cost is constructed. The experimental results show that compared with the traditional estimation model, the estimation accuracy of this method is higher and the estimation time is shorter.