Abstract: Counting the number of interference fringes has always been a headache in the Michelson interferometer experiment for measuring the wavelength of He-Ne laser.In this paper，we introduce the automatic counting software system based on smartphone.The software comes with a smartphone camera to capture the interference fringe image.We use the Fourier transform filter analysis to calculate the number of fringe throughout automatically.The system is simple to 　　operate and has a counting accuracy of up to 0.5 fringe，which greatly improves the measurement accuracy.With the popularity of smartphone applications，the system has broad application prospects.

Key words: Michelson interferometer, smartphone, automatic counting system