In order to make huge profits, the illegal traders add canthaxanthin to chicken feed to make fake native eggs, which seriously damages the rights and interests of consumers. Both canthaxanthin and yolk coloring (lutein, zeaxanthin and carotene) are linear polyene molecules with similar structures and similar molecular weights; they are extracted at the same time and are difficult to separate. The ultraviolet-visible spectra of canthaxanthin and yolk extract overlap seriously, so it is impossible to detect canthaxanthin by traditional spectroscopy. In this paper, ultraviolet-visible spectrophotometry and first derivative spectrophotometry were combined to establish a rapid method for the determination of canthaxanthin in egg yolk without separation after simple extraction, the interferences of lutein, zeaxanthin and carotene on the detection of canthaxanthin were effectively eliminated. Firstly, the yellow compounds in the yolk were extracted with a mixed solvent of ethanol and chloroform. The spectra of yolk extract and canthaxanthin standard solution were scanned by ultraviolet-visible spectrophotometer. Then the spectra were processed for first-order differential processing by Origin software and were smoothed to eliminate noise by Adjacent-Averaging method. According to the first derivative spectra’ characteristics of yolk extract, standard canthaxanthin sample and their mixture and the zero-cross point position of the first derivative spectrum of yolk extract, 448, 467 and 520~579 nm can be used as detection wavelength of canthaxanthin. The first derivative spectrum value of the mixture of yolk extract and the standard canthaxanthin solutions was plotted against the concentration of canthaxanthin to obtain the straight working line. The linear relationship and detection limit of the working line at 448, 467, 520 and 535 nm wavelengths were investigated. The results showed that the optimal detection wavelength of canthaxanthin was 520 nm. The linear regression equation of the working line at 520 nm was Y=0.001 01C+0.000 180 9 and R²=0.992 9. The linear range was 0~17.68 μg·mL^-1, and the detection limit was 0.58 μg·mL^-1. In order to verify the effectiveness of this method in actual sample measurement, three egg samples from different producing areas were added and recovered. The results showed that the average recovery of the samples ranged from 96.4% to 102.8%, and the relative standard deviation ranged from 2.53% to 5.67%. The method does not need complicated sample pretreatment steps and large-scale instruments; it is simple, accurate and low cost and can be used to detect canthaxanthin in egg yolk.