The invention relates to a near-ultraviolet source adjustment mechanism for a solar simulator, which includes an adapter ring, a body, a condenser lens, an adjustment cylinder, an inner focusing cylinder, an insulating sleeve and a lamp holder, and the adapter ring is sleeved on one side of the body. The condenser is fixedly connected to the adapter ring, the adjusting cylinder is connected to the other side of the body by rotation, the inner focusing cylinder is plugged into the body, the insulating sleeve is plugged into the focusing inner cylinder, and the lamp holder is plugged into the insulating sleeve, among which , there are four adjusting screws threaded on the insulating sleeve, the axis directions of the adjacent adjusting screws are vertical to each other and one end is in contact with the lamp holder, the other end of the adjusting screw passes through the focusing inner barrel and extends out of the body; the focusing inner There are several guide columns fixedly connected to the outer wall of the cylinder, and several guide grooves are opened on the adjustment cylinder. The guide columns pass through the body and extend into the guide grooves, so that the guide columns and the adjustment cylinder are slidably connected. The advantages of adjusting the position of the xenon lamp axis, horizontal direction, and vertical direction are unchanged.