High-speed lockstitch machine with an automatic thread trimmer which is provided with a new oil shielding system. The sewing machine which integrates the direct-drive motor, control box and control panel into a monolithic body is now provided with a new oil shielding mechanism. It not only eliminates oil stains on sewing products, but also further enhances workability and maintainability. In order to prevent oil stains on sewing products, the sewing machine has adopted the “Oil Shielding System” which is integrated into the sewing machine bed. The new structure contributes to the achievement of the maximum sewing speed of 5,000sti/min and also to increased productivity.