Heterocyclic ligand compound, catalyst composition containing the same, and application

The invention provides a heterocyclic ligand compound, a catalyst composition containing the same, and an application. A structure of the heterocyclic ligand compound is shown as a formula (I). In the formula (I), X represents O or S; and R1, R2, R3 and R4 are independently selected from hydrogen, alkyl, alkoxy and halogen. The catalyst composition provided by the invention comprises the heterocyclic ligand compound shown as the formula (I), a transition metal compound and a co-catalyst. The invention also provides an application of the catalyst composition in olefin polymerization, particularly olefin oligomerization. The formula (I) is shown in the description.