The invention provides a knife rest and 
light source structure of a 
slit lamp. The structure comprises a light-pervious cylinder structure and a 
light source base structure connected with the lower end of the light-pervious cylinder structure. The light-pervious cylinder structure comprises a 
triangular prism, a light-pervious cylinder lens cone, a first lens, an upper 
lens space ring and a second lens. The first lens, the 
lens space ring and the second lens are sequentially arranged in the light-pervious cylinder lens cone from top to bottom. The 
triangular prism is arranged on the top of the lens cone. The 
light source base comprises an upper blue-
ray disc, a lower blue-
ray disc, an opening and closing knife rest, a third lens, a lower 
lens space ring, a fourth lens, a light source lens cone, a 
bulb and a lamp holder. The upper blue-
ray disc is located on the lower blue-ray disc. The light source lens cone is sleeved with the opening and closing knife rest. The third lens, the lower lens space ring and the fourth lens are sequentially arranged in the light source lens cone from top to bottom. The 
bulb is arranged on the upper surface of the lamp holder. The lamp holder is arranged at the bottom end of the light source lens cone. The knife rest and light 
source structure of the 
slit lamp is compact in structure and convenient to use and can effectively reduce the size of the 
slit lamp.