Abstract: Use the general experiment equipment and optimal method to do the concrete mix proportion experiment.We use the dimension-reduction algorithm to make the apparent density function of concrete to change from multi-dimensional function to one-dimensional function,use the least square method to get correlation coefficient,use the number line method to choose the experiment,use the contouring method to get the extremum,then this extremum is the optimal mix proportion of concrete.At the construction location,we can get the experiment result at the same day,then use the seven days to investigate the strength.This method has been adopted for many times by international projects of the World Bank,one of them once have ever saved much concrete estimated about more than 3,000,000yuan（1992）.