Mechanical drawing is the basic and core course for majors in mechanics,and its teaching quality is related to students' learning of follow-up courses.However,the current teaching lays emphasis on of theoretical knowledge,which is away from actual production.It is not conducive to students mastering mechanical drawings,so the teaching method need to be reformed urgently.This paper proposes to integrate theory with practical drawing of components and parts,establishes a mechanical drawing teaching environment based on cognitive practice and a mechanical drawing teaching system based on engineering design.The reform will increase practical teaching with cognition of mechanical components and parts,strengthen learning parts expression methods,and draw strictly in accordance with the drawing process.As a result,it enhances students' practical ability of understanding,expression and drawing parts,and promotes the effect of students' observational and skillful learning.It is conducive to cultivating students' engineering design and improving students' engineering ability.