Disastrous water inrush often causes heavy property losses and even casualties, while the current theory and technology of mine water prevention and control can not accurately predict the time and place of disastrous water inrush in mine, so monitoring disastrous water inrush has become an urgent problem to be solved. Through the networked deployment of water level sensors in the roadway, this paper proposes a monitoring network for catastrophic water inrush in coal mine, and studies a multi-constraint and multi-objective optimal deployment method for the monitoring network. By setting three practical constraints of mining area, risk level of water inrush and installation at specified location, and constructing two objective functions of minimum total cost and minimum average monitoring time, a mathematical model is established, and then NSGA - Ⅱ multi-objective genetic algorithm is designed to solve the model. As results, the method can optimize the monitoring network for mine water inrush from two dimensions of time and space. The proposed method is then verified in the Beiyangzhuang coal mine in the North China. The results show that the average time of the catastrophic water inrush monitored can be controlled within 916 seconds by using only 28 water level sensors, and the higher the risk level of water inrush, the shorter the monitoring response time. Due to the constraints of installation at specified location, the monitoring network can also take into account monitoring the daily water inflow in the Beiyangzhuang coal mine.