Method for producing propylene oligomer

Provided is a method for producing a propylene oligomer with which it is possible to obtain a low-branched propylene oligomer with high selectivity. A method for producing a propylene oligomer, the method comprising: an oligomerization step in which propylene is oligomerized under conditions of less than 160 DEG C in the presence of at least one selected from the group consisting of a catalyst comprising a crystalline molecular sieve and a catalyst comprising phosphoric acid; a fractionation step for obtaining a fraction containing a propylene tripolymer, a propylene tetrapolymer, or a mixture thereof; and an isomerization step for isomerizing the propylene trimer, the propylene tetramer or a mixture thereof contained in the fraction in the presence of a catalyst containing phosphoric acid. 提供丙烯低聚物的制造方法，其能够以高选择率得到低支化的丙烯低聚物。丙烯低聚物的制造方法，其包括如下工序：在选自包含结晶性分子筛的催化剂和包含磷酸的催化剂中的至少1种的存在下，在小于160℃的条件下，对丙烯进行低聚物化的低聚物化工序；得到含有丙烯三聚物、丙烯四聚物或它们的混合物的馏分的分馏工序；以及，在包含磷酸的催化剂的存在下，对前述馏分中包含的丙烯三聚物、丙烯四聚物或它们的混合物进行异构化的异构化工序。