The invention discloses a method of determining the height and diameter of an internal combustion engine smoke exhausting pipe and an internal combustion engine. The method includes steps of 1, measuring the pressure and smoke temperature in the smoke exhausting pipe, and calculating the smoke density of the smoke exhausting pipe inside; 2, measuring the smoke flow in the smoke exhausting pipe, and calculating the smoke flow speed of the smoke exhausting pipe; 3, determining the smoke loss of the smoke exhausting pipe according to the smoke density and smoke flow speed; 4, measuring the air density and the absolute pressures at the inlet section and outlet section of the internal combustion engine smoke exhausting pipe, and acquiring an energy conservation equation of the smoke exhausting pipe according to the air density, the absolute pressure, the smoke density, the smoke flow speed and the smoke loss; 5, determining the height and diameter of sections of the smoke exhausting pipe according to the energy conservation equation of the smoke exhausting pipe. Accurate determination of the height and diameter of the internal combustion engine smoke exhausting pipe can be realized, so that the coordinative benefits of economy and environment are unified.