Adjusting auxiliary tool and projection system

The invention discloses an adjusting auxiliary tool and a projection system. The projection system is used for image projection on a plane and comprises a light curtain generating device, an adjusting mechanism and the adjusting auxiliary tool, wherein the light curtain generating device is used for projecting a light curtain on the plane, the adjusting mechanism is connected with the light curtain generating device, the adjusting auxiliary tool comprises at least one positioning pillar, and each positioning pillar is provided with a surface and an indication mark arranged on the surface. The positioning pillars can be arranged on the plane at the same time to enable projection images of the light curtain to be correspondingly formed on the surfaces of all the positioning pillars. The adjusting mechanism is used for adjusting the arrangement of the light curtain relative to the plane according to the relationship between the projection images and the corresponding indication marks, and further the problem of unstable touch operation caused by oblique arrangement of the light curtain is avoided.