Hierarchical Latent Tree Analysis (HLTA) is a new method of topic detection. However, HLTA data input uses TF-IDF selection term, and relies on EM algorithm for parameter estimation. To solve this problem, a method of accelerating part of speech weight (PWA-PEM-HLTA) is proposed based on Progressive EM-HLTA (PEM-HLTA). Experimental results show that this method improves the execution efficiency of PEM-HLTA, averaging 4.9 times speed, and improves the speed of 6 times in the best case.