A method and device for measuring dominant wavelength and color purity of LED lamp, and an electronic equipment. The method includes: establishing standard data; calculating difference and distance between chromaticity coordinate in the standard data and the chromaticity coordinate of equal-energy white light; calculating an included angle between a vector formed by the chromaticity coordinate of equal-energy white light to each standard chromaticity coordinate and a positive direction of x axis; performing a one-way processing on the included angle to form included angle data; calculating an included angle intermediate value; determining minimum and maximum values of the included angle intermediate value; calculating a dominant wavelength coefficient and a measured included angle intermediate value; calculating a wavelength interval corresponding to the included angle intermediate value; calculating a dominant wavelength intermediate value and x difference by interpolation calculation; and obtaining dominant wavelength and color purity of the LED lamp.