Disclosed are a resistance-reducing pointed cap and a triangular water separator of a submarine. The resistance-reducing pointed cap and the triangular water separator of the submarine can reduce resistance when the submarine navigates in the water. The resistance-reducing pointed cap is welded on the front of a submarine hull. The triangular water separator is welded on the front of an elliptic cylinder on the back of the submarine. An air inlet-outlet hole and a water inlet-outlet hole are preformed in the top and bottom of the joint of the resistance-reducing pointed cap and the submarine hull separately. An air inlet-outlet hole and a water inlet-outlet hole are preformed in the top and bottom of the joint of the triangular water separator and the elliptic cylinder separately. The air inlet-outlet holes and the water inlet-outlet holes are used for adjusting the pressure reduction when the submarine is in deepwater and weight reduction when the submarine floats to the surface. The resistance-reducing pointed cap and the triangular water separator have the common characteristic of small front face areas, thereby being capable of reducing resistance when the submarine navigates in the water.