The present invention discloses a microbubble generator, comprising a liquid inlet, a gas inlet, a bubble outlet and a gas-liquid mixing chamber and characterized in that a gas-liquid interface part of the gas-liquid mixing chamber is provided with air holes with an angled structure, and tips of the angled structures of the air holes point to a flowing direction of a liquid. When gas is blown into the liquid, on the gas-liquid interface, the gas passing through the air holes is sheared into microbubbles by the tips of the angled structures of the air holes since the liquid on one side flows fast, the equivalent diameter of a gas passage at the tips of the angled structures tends to be infinitely small along the flowing direction of the liquid, the generated bubbles have very small diameter, retention time of the bubbles in a liquid phase is greatly prolonged, and gas-liquid mass transfer efficiency is significantly improved. The bubble outlet is further provided with a sharp-tooth structure, the microbubbles that gather in large bubbles can be dispersed, and gas-liquid mixing effect is guaranteed.