1, ignoring the objective laws of economic development, unilaterally pursuing the high speed of economic construction, and lacking a comprehensive understanding of China's national conditions (Great Leap Forward Movement)

2. Ignore the development level of productive forces, unilaterally reform the relations of production, wrongly put forward the slogan of taking class struggle as the key link, and ignore the development of productive forces (people's commune movement)

3. The most important thing is that we didn't stick to the judgment of the Eighth National Congress on the main contradiction in China in practice, which led to a series of left-leaning mistakes, seriously affected China's economic development, widened the gap with western developed countries, and formulated policies that exceeded the basic national conditions in the primary stage of socialism.