Mathematics core accomplishment is a topic in the field of education research. It is of practical significance and practical value to deepen the reform of basic education mathematics curriculum. At present, the six core qualities are: mathematical abstraction, mathematical reasoning, mathematical operation, mathematical modeling, visual imagination and data analysis. Among them, mathematical operation ability is one of the core qualities of mathematics, which also plays a decisive role in students' academic performance and affects the study of other subjects. Since the resumption of the college entrance examination, the ministry of education has made several large-scale adjustments to the teaching syllabus. The requirements of the syllabus for students have been changed from the need to "cultivate" students' operational ability to the need for students to "have" operational ability. It can also be seen that computational ability plays a very important role in the process of students learning mathematics. For junior high school students, mathematical calculation ability is the most basic ability that students should have, and it will affect the effect of students' learning of mathematics. The computing ability of junior high school students has a great impact on students' thinking ability, learning quality of mathematics and learning habits of mathematics, and has a decisive impact on the improvement of students' comprehensive ability of mathematics learning. We need to effectively understand the factors affecting the mathematical calculation ability, and put forward the corresponding countermeasures to improve the calculation ability, comprehensive and efficient to improve the mathematical calculation ability of junior high school students. In the end, this study further cultivated junior high school students' arithmetic ability through four aspects: first, it emphasized the foundation to help students grasp the mathematical arithmetic law; Second, pay attention to training, improve the comprehensive ability of students; Third, pay attention to standardize and develop good computing habits; The fourth is to cultivate interest in computing and stimulate learning desire.