Construction machine comprising a hydraulic system, comprising: electronic hydraulic pumps (110a and 110b) which are pressure control type variable capacity pumps; a plurality of main control valves (120a, 120b, 120c, and 120d) configured to selectively control a movement of working oil discharged from the electronic hydraulic pumps (110a and 110b); a plurality of working actuators (140a and 140b) and travel motors (130a and 130b) driven with working oil supplied from a main control valve corresponding to each of the plurality of main control valves (120a, 120b, 120c, and 120d); and an electronic control unit configured to control a discharge flow rate of the working oil of the electronic hydraulic pumps (110a and 110b) based on flow rate signals (116a and 116b) of the electronic hydraulic pumps (110a and 110b) and an operative amount of a joystick, characterized in that, when the electronic control unit is not able to perform a normal control due to a failure of transmittance of the operative amount of the joystick to the electronic control unit, the electronic control unit performs an emergency control of permitting the electronic hydraulic pumps (110a and 110b) to discharge the working oil with a maximum pressure by outputting predetermined pressure control signals to the electronic hydraulic pumps (110a and 110b), and the electronic control unit performs a predetermined control that permits the electronic hydraulic pumps (110a and 110b) to discharge the working oil at a predetermined flow rate and at a minimum pressure when the joystick is in a neutral state during the emergency control, and further comprising: center bypass valves (170a and 170b) generally closed during the normal control of the electronic control unit, wherein the electronic control unit switches a type of the hydraulic system to an open type by operating the center bypass valves (170a and 170b) when the electronic control unit is not able to perform the normal control; and wherein in the open-type system switched according to the operation of the center bypass valves (170a and 170b), when the electronic hydraulic pumps (110a and 110b) have a pressure equal to or higher than a predetermined reference pressure and maintain a maximum swash plate angle for a predetermined reference time, the electronic control unit recognizes that the joystick is in a neutral state. a plurality of main control valves (120a, 120b, 120c, and 120d) configured to selectively control a movement of working oil discharged from the electronic hydraulic pumps (110a and 110b); a plurality of working actuators (140a and 140b) and travel motors (130a and 130b) driven with working oil supplied from a main control valve corresponding to each of the plurality of main control valves (120a, 120b, 120c, and 120d); and an electronic control unit configured to control a discharge flow rate of the working oil of the electronic hydraulic pumps (110a and 110b) based on flow rate signals (116a and 116b) of the electronic hydraulic pumps (110a and 110b) and an operative amount of a joystick, characterized in that, when the electronic control unit is not able to perform a normal control due to a failure of transmittance of the operative amount of the joystick to the electronic control unit, the electronic control unit performs an emergency control of permitting the electronic hydraulic pumps (110a and 110b) to discharge the working oil with a maximum pressure by outputting predetermined pressure control signals to the electronic hydraulic pumps (110a and 110b), and the electronic control unit performs a predetermined control that permits the electronic hydraulic pumps (110a and 110b) to discharge the working oil at a predetermined flow rate and at a minimum pressure when the joystick is in a neutral state during the emergency control, and further comprising: center bypass valves (170a and 170b) generally closed during the normal control of the electronic control unit, wherein the electronic control unit switches a type of the hydraulic system to an open type by operating the center bypass valves (170a and 170b) when the electronic control unit is not able to perform the normal control; and wherein in the open-type system switched according to the operation of the center bypass valves (170a and 170b), when the electronic hydraulic pumps (110a and 110b) have a pressure equal to or higher than a predetermined reference pressure and maintain a maximum swash plate angle for a predetermined reference time, the electronic control unit recognizes that the joystick is in a neutral state. center bypass valves (170a and 170b) generally closed during the normal control of the electronic control unit, wherein the electronic control unit switches a type of the hydraulic system to an open type by operating the center bypass valves (170a and 170b) when the electronic control unit is not able to perform the normal control; and wherein in the open-type system switched according to the operation of the center bypass valves (170a and 170b), when the electronic hydraulic pumps (110a and 110b) have a pressure equal to or higher than a predetermined reference pressure and maintain a maximum swash plate angle for a predetermined reference time, the electronic control unit recognizes that the joystick is in a neutral state.