Single shot MultiBox detector has been successfully applied in the dom ain of target detection,while its average accuracy of ship in the public datasets is obviously lower than that of other rigid-body targets.Meanwhile,the number of ship in the public datasets existing is small and the category of ship is single.In order to impro ve the accuracy of detection,a single stage ship detector based on the improved VGG network was proposed.The alternating connection struc ture of asynchronous convolution and maximum pooling was added to the underlying network of VGG to ensure real-time detectio n and improve the average accuracy of targets detection.In order to increase the number and the types of ships needed for tra ining,images of ships were widely collected by means of internet skills,and a dataset containing 22507ships was e stablished,among which 6902ships were subdivided into seven types.After the training of VOC2007trainval and VOC2012trainval with Nominal Res olution of 300×300,the average precision of SSSD in VOC2007test can reach 79.3%,and the average speed of ship detections exceeds 40fps.After transforming the corresponding parameters and training on proposed datasets,the average accuracy of large clas s ships detection exceeds 84%,and that of seven class ships exceeds 89%,leading the existing similar algorithms for ships detection.