The spatial-temporal distribution of crowds as well as evacuation safety and efficiency are impacted by the layout of indoor obstacles. To investigate the effect, a crowd evacuation model for a single room with a single exit and obstacles is proposed in this study. Three different influencing factors (i.e., obstacle length, the distance between an obstacle and the exit, and the distance between the obstacle center and exit center) are used to analyze their impacts on evacuation efficiency and safety. The experimental results reveal that the obstacle length is directly proportional to evacuation efficiency and is inversely proportional to evacuation safety. The evacuation efficiency and safety are directly proportional to the distance between the obstacle and the exit and are inversely proportional to the distance between the obstacle center and exit center. Additionally, a multi-objective evolutionary algorithm is used to optimize the layout of the indoor obstacles, and the obtained results can provide an important reference for decision-makers to balance evacuation efficiency and safety.