In this thesis , we first introduce give the definition of hidden markov models . then the methods to solve the three basic problems in the application of hidden markov models are introduced , namely three basic arithmetic : forward - backward algorithm , viterbi algorithm , baum - welch algorithm . also we present commonly model of hidden markov processes dynamic system 在这篇论文中,首先给出了隐马尔科夫模型的定义,接着介绍了隐马尔科夫模型实际应用中所面临的三大基本问题的解决方案,即隐马尔科夫模型三大基本算法:前向一后向算法、 viterbi算法、 baum ? welch算法。