In order to solve the problem that the pin of butterfly laser connected with lead wire breaks in the sweep frequency vibration test, the finite element analysis model is established with different pin length to reflect the influence of lead wire. The stress of the pin is analyzed by mode superposition method under the condition of 20 g and 20 ~ 2 000 Hz sinusoidal sweep frequency vibration. Based on Miner criterion, the life of pin under vibration is calculated. The analysis results show that the natural frequency of the original laser pin is higher than 2 000 Hz. After connecting to the lead wire, the natural frequency will be reduced to less than 2 000 Hz, and the resonance will occur under the vibration condition. It is also shown that if the lead wire is fixed appropriately, the natural frequency can be increased to more than 2 000 Hz to avoid resonance. Moreover, the results indicate that the original laser pin has infinite life under vibration condition, but the life of the pin connected by lead wire is greatly reduced. The pin life can be increased to infinite life by fixing the lead wire appropriately.