The invention discloses a universal type table lamp pen cap which comprises a shell, a solar photovoltaic cell, a support, an LED lamp, a first bolt, a second bolt, a third bolt, a rechargeable battery, a control circuit, a power switch and a brightness adjusting knob. The LED lamp, the brightness adjusting knob, the power switch and the rechargeable battery are electrically connected in sequence.The solar photovoltaic cell is connected with the rechargeable battery through the control circuit. The shell is in a cylinder shape and internally comprises a first cavity, a second cavity and a third cavity to top to bottom. The first cavity is used for containing the support and the LED lamp, the second cavity is used for containing the rechargeable battery, the third cavity is used for allowing a pen body to be inserted therein, and the first, second and third bolts are matched with three threaded holes in the shell and used for fixing the pen body inserted into the third cavity. The universal type table lamp pen cap can provide brightness supplement when environment light is insufficient, relieve eye fatigue, protect eyesight and adapt to different writing environments. The pen cap can be applied to any pen with the inner diameter smaller than that of the pen cap, the using value is greatly improved, and the using range is greatly enlarged.