The invention discloses an authentication instrument of a Bernoulli equation, comprising a case and a ball. The case is provided with an air inlet on the front and a rectangular air outlet on the lateral surface, the ball is fixedly connected with a connecting rod, the upper end of the connecting rod is articulated with the lateral surface of the air outlet, the diameter of the ball is smaller than the height of the air outlet, and the positive projection of the ball on the lateral surface is positioned between an extension line of the upper edge of the air outlet and an extension line of thelower edge and is not crossed with the air outlet. The authentication instrument of the Bernoulli equation has simple structure, low manufacture cost, simple operation in experiments and intuitive and sensible experimental phenomena. The instrument is not only suitable for physical teaching in colleges and universities to be popularized as an authentication experiment, but also suitable for experimentally authenticating the Bernoulli equation by engineering researchers.