Two periods of fluid movement are recognized in the Big Daqing Anticline (BDA), Songliao Basin. The first period is controlled by the diagenetic process characterized by isolated fluid inclusions inside the authigenic minerals; the second period is controlled by the tectonic movement characterized by linearly distributed inclusions along the fissures or cracks of the autogenetic minerals and a homogeneous temperature higher than the maximum burial temperature. Small-scale hydrocarbon migration during the first episode is indicated by a low content of hydrocarbon fluid inclusions (GOI<5%), while large-scale hydrocarbon migration in the second episode is indicated by a high content of hydrocarbon inclusions (GOI>15%) and a strong fluorescence of yellow-white or brown-yellow. A systematic authigenic illite dating deciphers a rapid hydrocarbon charging process during the tectonic folding. The hydrocarbon accumulation process in the BDA is a typical anticlinal hydrocarbon charging indicated by the negative age-depth distribution model which applies in the flank of BDA with an elevation <－900m, and the positive age-depth distribution model which is suitable in the centre with a height>－900m. The age distribution model indicates that all the strata under the main seal level have undergone hydrocarbon charging in a relatively long short period of 59-69 Ma with reserves >7×109 t (daily charging>2t), which is an efficient but instant hydrocarbon charging process rather than a steady one.