The invention discloses a riding mower with a noise reduction measure and hydraulic stepless speed change. The riding mower comprises a steerable front axle, a drivable rear axle with hydraulic stepless speed change, a frame with a double-protection lever, a mowing device with noise reduction, an engine with a noise elimination groove, a head housing with noise reduction, a noise elimination air filtering net, a saddle with noise reduction and a grass collection box with noise reduction, wherein the front axle is connected with two front wheels; the drivable rear axle is ocnencted with two rear wheels; the frame is arranged above the four wheels; the mowing device is arranged below the frame; the engine is arranged above the frame close to the front side; the saddle is arranged on the middle part above the frame close to the rear side; the grass collection box is arranged behind the mower; in addition, for personal protection of a riding operator, accessories such as earplugs, sound-proof cotton, ear muffs and a sound-proof helmet are arranged. The invention also introduces a heightening quadrilateral structure, diagrammatic design of a mowing part, a preferable thinking method and a comprehensive application method of the noise reduction measure to the entire mower.