Vibration failure is a common and serious failure for the aero-engine. Engine dynamic balance is an important measure to reduce the engine vibration. The advanced aircrafts are capable of calculating the engine low pressure rotor balance solution using the airborne equipment and vibration data collected during the regular flights. The engine balance coefficients are the critical factor of the calculation. A lot of ground and flight tests are needed to collect data to calculate the engine balance coefficients.This article introduces the calculation method of the balance coefficients, format of the balance coefficients, studies the test procedure of obtaining the balance coefficients data and gives the processing method of the obtained balance coefficients data.