It is a key issue to accurately grasping the vibration damping characteristics of Beta damping lines in the design of anti-vibration of long-span transmission lines. Based on the characteristics of aeolian vibration of damping line, the calculation formula of resonance frequency and lace length of Beta damping line is derived, and the reasonable range of lace length of damping line is analyzed. Combined with IEEE vibration test guide for transmission line, the test model of vibration damping characteristics of Beta damping line for long-span transmission line is designed and made. The influence of the length and the quantity of lace and the sag of lace on the aeolian vibration of long span transmission line is studied. The results show that the lace length of Beta damping line is closely related to the resonance frequency, mass and bending rigidity of materials, and the lace length should not be too long; the lace length of damping line has a great influence on the aeolian vibration of transmission line. The lace length is different, the vibration attenuation effect is also different under different excitation frequency, and the damping line with multiple lace combination has a wider anti-vibration frequency band and anti-vibration effect than that with single lace damping line. The influence of lace sag of Beta damping line on the aeolian vibration of transmission line is small.