Abstract: On the basis of the laser beam moment analysis theory, the concept ofeffective integral region is proposed. The relation between dynamic range of themeasurement system and effective integral region is discussed. The method toenlarge effective integral region is given. Taking the measurement of fundamentalGaussian beam and high order Hermite-Gaussian beam as examples, the analysis ofthe dynamic range effect on measurement precision is made. The data indicate thatthe dynamic range have no great effect on measurement precision. The properdemand for the dynamic range in laser beam measurement is also proposed.