The invention relates to a catalytic
system for preparation of wide-distribution
polyolefin, and application of the catalytic
system. The catalytic
system comprises a
solid catalyst component (A), a cocatalyst (B) and a first external
electron donor (ED1), wherein the component (A) is a
magnesium halide loaded Ti
solid component and contains a composite internal
electron donor (ID); the first external
electron donor (ED1) is selected from one or more of compounds as shown in a general formula (1), (the formula is as shown in the description); and the R1 is selected from C1-C6
alkyl, C3-C8 naphthenic base, C6-C14
aryl or C6-C14 ceteroary, R2 is selected the formulas as shown in the description, and R3 is selected from OR1, R2, C1-C6
alkyl and C3-C8 naphthenic base. When being applied to
olefin polymerization, the catalytic system has various advantages: catalytic activity and
hydrogen sensitivity are high; and the
polymerization product is high in isotactic index, wide in molecular
weight distribution and high in weight-average molecular weight.