A reasonable millisecond time control method for excavation blasting of a tunnel is provided, and includes: acquiring physical mechanical parameters to establish a millisecond blasting model, and designing four dimensions blasting parameters of explosive quantity, hole number, inter-hole millisecond and inter-row millisecond; simulating, based on the millisecond blasting model, a blasting process of an explosive package using blasting parameters to obtain a blasting vibration curve; obtaining single-hole blasting vibration waveforms, solving a vibration synthesis curve through a vibration synthesis theory; comparing the vibration synthesis curve with the blasting vibration curve to obtain a coupling relationship of blasting parameters; determining a target group of explosive quantity and hole numbers, determining a target millisecond through the coupling relationship of blasting parameters, and relating a millisecond blasting control strategy to control, and it is used for tunneling project to reduce cut blasting vibration intensity and achieve precise and intelligent control of millisecond blasting.