Abstract: A cuttings transport test is carried out with a full size stimulator to reveal the characteristics of cuttings migration in the sidetracked horizontal well. An annular return velocity of 0.85~1.2m/s, and a deviation angle of 40~60° are determined as the critical values of cuttings beds settling. This paper presents the specific parameters and indexes for evaluating the cuttings carrying capacity and suggests a critical value of 1.5, which may be used for reference in drilling fluid program, and an annular return velocity of 1.2~2.0m/s is chosen for field drilling according to the test. Drilling practice in Daqing Oilfield proves the accuracy of the test results.