The invention provides a device for measuring pulse waves and blood pressures. The device comprises a wrist strap, a pulse wave sensor, a balloon, a gas source, a pressure sensor, a collection unit and a calculation unit, wherein the wrist strap is used for wrapping the wrist of the human body, and the balloon is arranged in the wrist strap and capable of being pressurized and depressurized. The pulse wave sensor is arranged on the wrist strap, and acquires first pulse waves through directly collecting pulse vibration pressure from the radial artery in real time. The gas source supplies gas with the pressure controllable to the balloon. The pressure sensor is arranged on a conveying pipeline of the gas source and the balloon and used for detecting gas pressures in the wrist strap. The collection unit collects the first pulse waves and the gas pressures. The calculation unit is connected with the collection unit and calculates the mean blood pressure, the systolic pressure and the diastolic pressure according to the gas pressures with the pulse waves as correction parameters.