We measured the carrier transit time of ITO/P3HT(poly(3-hexylthiophene))/Al devices by using the photocurrent time-of-flight method which the P3HT films were drop-casting from its chloroform solution,the data range of the mobility was relatively large.The hole mobilities of P3HT were regularly divided into three groups by the analysis of Poole-Frenkel plot.It can be inferred that there are at least 3 different carrier transport mechanisms in poly(3-hexylthiophene).