This paper proposes a deep learning algorithm for estimating pig weight. The proposed algorithm estimates the weight of a pig using the point cloud obtained through a mobile device. The proposed model is based on the PointNet which is widely used in the point cloud data. Through the optimization of the PointNet, the proposed method not only improves the accuracy, but also reduces the computational complexity. The accuracy (82.4 %) of the proposed method was about 3 % higher than that of the conventional method (79.4 %). Also, the numbers of the trainable parameters for the PointNet and the proposed method were 3,114,771 and 150,554, respectively. That is, the proposed method used only 5 % of trainable parameters compared to the PointNet. The developed model makes it easier and faster to measure the weight of a pig than the conventional method.