Mini-diode lamp board and light-emitting device are provided. The board includes a substrate, luminance signal lines arranged in a first direction and extending in a second direction, and control signal lines arranged in the second direction and extending in the first direction. The board has sub-regions each including a drive chip and a LED lamp group; drive chips corresponding to a row of sub-regions arranged in the first direction are electrically connected to the same control signal line; drive chips corresponding to a column of sub-regions arranged in the second direction are electrically connected to the same luminance signal line; and the drive chip obtains a luminance signal provided by the luminance signal line under the control of a control signal provided by the control signal line, and controls a corresponding LED lamp group to emit light according to the luminance signal.