Laboratory safety has become a key concern which attracts many attentions from governments and academic institutes. Besides, according to some published reports, about 70% of accidents are closely related to human related risks. Therefore, to the laboratory safety, it is necessary to carry out some particular efforts to evaluate human related risk during operation an experiment. However, there is limited research to analyse laboratory from the aspect of human related risk. In order to assess human related risk, this study provides an integrated method which contains Hierarchy Task Analysis (HTA), Human Error Assessment and Reduction Technique (HEART) and risk matrix. HTA method is used to decompose experiments into several steps for further analysis. Then widely used human reliability method HEART is used to calculate the human error probability in each decomposed step by evaluating the corresponding Error Producing Conditions (EPCs) for each step. Finally, a risk matrix is constructed to evaluated the risk level of human in each step. The proposed method is applied to a risky experiment (the effect of magnetic field on acetylene explosion rate and pressure), the human related risk level and several risky steps are identified.