One of the common thoracic trauma is open thoracic trauma. This causes the pleural cavity opened, then the liquid and air enter into it and disturb the respiratory system and cardiopulmonary function. To handle open thoracic trauma requires installation of a tracheostomy pipe that is connected with water seal drainage and low pressure suction. Suction pump generally has a high pressure so that it requires a Thoracic Suction Based on Arduino Uno which is a low pressure liquid suction device equipped with excess liquid safety and temperature safety of the pump motor. The working principle of this tool is by sucking the liquid and air trapped inside the thorax cavity. The method is by measuring the pressure produced by the pump motor based on the input voltage given using Fluke 4 DPM. Based on measurements for 12 times, maximum suction pressure amounting to -18.8 mmHg with 12 volt input voltage, and the lowest pressure is amounting to -1.2 mmHg with 1 volt input voltage. Safety of the motor temperature can work well marked with an alarm when the motor temperature is 45˚C and the pump motor is off. When the temperature drops, the motor returns to work and the alarm turns off. Safety of excess fluid is indicated by an alarm that sounds when the liquid in the tube reaches 400 ml.