The invention discloses a horizontal shaft type concrete mixer. The horizontal shaft type concrete mixer comprises a device body, a mixing barrel, a mixing rod, a supporting plate and a control electric box, wherein a supporting plate is seamlessly welded to the left side of the top end of the device main body, the right side of the top end of the device body is fixedly connected with a control electric box through a nut, the right side of the supporting plate is fixedly connected with a movable supporting shaft through the nut, and the right side of the movable supporting shaft is fixedly connected with the mixing barrel through the nut. According to the horizontal shaft type concrete mixer, the top end of mixing blades are seamlessly welded with a fixed plate, a large amount of concreteis arranged in the mixing barrel in the mixing process to cause the deformation of the mixing blades, the top end of the mixing blades is seamlessly welded with a fixing plate, so that the mixing blades can be mutually fixed and supported, the mixing blades are not easy to bend, and then the problem that mixing is not uniform an existing horizontal shaft type concrete mixer due to the fact that the mixing blades are easily bent for a long time is solved.