Taking the shallow light rail tunnel project of Sports Park Station in Chongqing rail transit circle as the research background, made blasting vibration effect experiments of construction channel blasting and drilling excavation undercrossing“ Two Rivers Spring City”. In the early drilling and blasting, calculated the blasting vibration attenuation parameters by monitoring parameters，and through measuring the blasting caused vibration velocity waveforms of different building floors at the light rail tunnel undercrossing buildings, studied the building vibration characteristics as well as the blasting seismic wave propagation and attenuation laws. The research found that the blasting vibration attenuation parameters were =1.88 and k=99.43, and in the process of shallow buried light rail tunnel drilling and blasting excavation，the blasting vibration velocity of the vertical direction is significantly greater than that of horizontal direction，so the study of blasting vibration propagation and attenuation laws as well as the influences of vibration on buildings are premised on the blasting vibration velocity in vertical direction; The blasting vibration velocity increased with the increment of floors at the bottom, decreased with the increment in the middle and increased again with the increment at the top, it did not decrease with the increase of the building floors, which did not meet traditional Steve sadove’s attenuation law. Meanwhile compared the measured blasting vibration velocity before and after light rail tunnel undercrossing buildings, the later exists blasting vibration amplification effect and the magnification is about 1.32~1.69 times.