The three-dimensional object detection algorithm based on point cloud is one of the key technologies in the autonomous driving system. Currently， the voxel-based anchor-free detection algorithm is a research hotspot in academia， but most researches focus on designing complex refinement stage， at the expense of huge algorithm latency， to bring limited performance improvement. Although the single-stage anchor-free point cloud detection algorithm has a more streamlined detection process， its detection performance cannot satisfy the needs of autonomous driving scenarios. In this regard， based on the anchor-free detection algorithm CenterPoint， a single-stage anchor-free point cloud object detection algorithm for autonomous driving scenarios is proposed in this paper. Specifically， the encoding and decoding sparse module is introduced in this paper， which greatly promotes the information interaction of the spatial non-connected areas of the three-dimensional feature extractor， ensuring that the three-dimensional feature extractor can extract features that satisfy various target detection. In addition， considering that it is challenging to adapt the existing two-dimensional feature fusion backbone to the center-based head， in this paper self-calibrated convolution and large kernel attention modules are introduced in to effectively extract point cloud features of the target area， which are then gathered into the center point area， thereby improving the algorithm's recall and accuracy of the target. The proposed algorithm in this article is trained and experimentally verified on the large-scale public dataset of nuScenes. Compared with the benchmark algorithm， mAP and NDS are increased by 5.97% and 3.62% respectively. At the same time， the actual road experiments with the proposed algorithm are conducted on a self-built vehicle platform， further proving the effectiveness of the proposed algorithm.