A computer-implemented parameter optimization method for CNC machining, the method comprising: establishing a one-to-one functional relationship between each parameter and each performance index based on function relationships between each performance index and all parameters established in advance, wherein the parameters are CNC machine tool parameters; determining current correlation coefficents between each parameter and each performance index based on the one-to-one function relationships comprising: for a current value of each parameter, determining a tangent slope at the current value in a function image of the one-to-one functional relationship between each parameter and each performance index as the current correlation coefficient between the parameter and the performance index; obtaining a current weight of each performance index; according to current weights and current correlation coefficients, obtaining a current influence coefficient of each parameter on a comprehensive performance of each performance index; and determining a parameter whose current influence coefficient reaches a set high threshold as an important optimization parameter, or determining a first one or more parameters with higher current influence coefficient as important optimization parameters; for each two parameters of the parameters, calculating a current correlation coefficient of the two parameters according to the current weights and the current correlation coefficient between the two parameters and the performance index, and determining the parameter whose current correlation coefficient with the important optimization parameter meets set requirements as an adjustment parameter; and performing parameter optimization based on the determined important optimization parameters and the determined adjustment parameters. establishing a one-to-one functional relationship between each parameter and each performance index based on function relationships between each performance index and all parameters established in advance, wherein the parameters are CNC machine tool parameters; determining current correlation coefficents between each parameter and each performance index based on the one-to-one function relationships comprising: for a current value of each parameter, determining a tangent slope at the current value in a function image of the one-to-one functional relationship between each parameter and each performance index as the current correlation coefficient between the parameter and the performance index; obtaining a current weight of each performance index; according to current weights and current correlation coefficients, obtaining a current influence coefficient of each parameter on a comprehensive performance of each performance index; and determining a parameter whose current influence coefficient reaches a set high threshold as an important optimization parameter, or determining a first one or more parameters with higher current influence coefficient as important optimization parameters; for each two parameters of the parameters, calculating a current correlation coefficient of the two parameters according to the current weights and the current correlation coefficient between the two parameters and the performance index, and determining the parameter whose current correlation coefficient with the important optimization parameter meets set requirements as an adjustment parameter; and performing parameter optimization based on the determined important optimization parameters and the determined adjustment parameters.