Abstract: Disclosed is a fan. The fan includes a support, a first motor, a first blade, a second motor, a second blade and an electronic control board. The first motor and the second motor are both installed on the support. The first motor is coaxial with the second motor. The first motor has a first rotation shaft and the second motor has a second rotation shaft. The first blade is installed on the first rotation shaft. The second blade is installed on the second rotation shaft. A torsion direction of the first blade is opposite to a torsion direction of the second blade. The electric control board is electrically connected to the first motor and the second motor, and includes a speed ratio adjustment device. The fan can provide a variety of air outlet modes and can quickly adjust between different air outlet modes.