Abstract: In recent years，cosmic ray detection has developed rapidly. Space-borne and ground-based cosmic ray experiments have achieved many important results，breaking the lull in cosmic ray research that has lasted for many years. Hybrid observation with multi-techniques is the only way to achieve accurate measurement of the energy spectrum and composition of cosmic rays，while very high energy gamma ray astronomy provides a possible key to the century-old mystery——the origin of cosmic rays. The Large High Altitude Air Shower Observatory project will explore the basic problems in this field with its highest sensitivity to ultra-high energy gamma rays，highest survey sensitivity to very high energy gamma ray sources，and widest cosmic ray energy coverage.