The invention discloses a device for performing waste heat recovery by using an exhaust pipe and a control method. An engine exhaust pipe adopts a double-layer structure and is combined with a Rankine cycle system; and due to control, waste heat recovery can be realized, and exhaust temperature heat treatment can also be realized. Under the high-speed high-load condition, a working medium channel in the double-layer exhaust pipe is filled with organic working media, the exhaust pipe working medium channel serves as a Rankine cycle evaporator, waste gas heat in the exhaust pipe is absorbed by the working media so as to recover the energy, and the influence of exhaust gas high temperature on the peripheral parts of the engines can be reduced; and in the startup stage and under the low-exhaust-temperature low-load condition, the double-layer exhaust pipe is filled with static air, the exhaust pipe has a heat insulation effect, the waste gas energy loss is reduced, and the engine exhaust gas is subjected to thermal insulation.