The invention relates to the technical field of petrochemical products, in particular to a method of using methyl isopropanolamine and epoxypropane to continuously produce N-methyl diisopropanolamine. The method includes: well mixing methyl isopropanolamine and epoxypropane in a mixer, and enabling a mixture to enter a reactor for reaction; distilling an obtained crude product containing N-methyl diisopropanolamine in a rectifying tower to obtain a refined product, N-methyl diisopropanolamine. The method fills in a gap in continuously producing N-methyl diisopropanolamine, can produce high-quality high-yield N-methyl diisopropanolamine efficiently and stably and has the advantages of saving manual labor and lowering production cost.