Law is an important part of Althusser's thought. He profoundly criticized the mechanism of capitalist law from the perspective of 'reproduction.' First, the law cannot be separated from the relations of production. In order to maintain capitalist relations of production, the law covers up the exploitation in the process of capitalist production. The key methods are to determine the ownership of the means of production and products and confuse the technical division of labor and social division of labor in the process of labor. It demands the submission of legal subjects, seducing and tempting subjects through the ideological function of law so that they will actively and willingly accept the restriction of law. Secondly, the law and the State are integrated. The 'surplus-violence' that the ruling class holds over the ruled class is transformed by law into legal State power, and the State power shapes individuals into subjects and endows subjects with rights through law, with the aim of the reproduction of capitalist relations of production. In addition, at the end of the article, I also mention Althusser's preliminary conception of communist law.