The invention provides a small modularized solar water quality buoy for a culture pond. The buoy comprises a floating body, a waterproof electric box is arranged on the floating body, and a storage batter, a charge-discharge controller and a wireless communication module are mounted in the waterproof electric box. A solar battery panel is arranged above the waterproof electric box, sensor mounting rods penetrate through mounting holes formed in the floating body and are fixed to the floating body through mounting rod fixing supports, and the heights of the sensor mounting rods can be vertically adjusted. Water quality sensors are fixed to the tail ends of the sensor mounting rods to enable the water quality sensors to immerge into water, and communication antennas of the buoy are mounted on the upper portions of the sensor mounting rods. The solar battery panel is fixed to the buoy through a solar battery panel support, the waterproof electric box is provided with waterproof quick connectors, and electric cables led out of the waterproof electric box are connected with the communication antennas on the upper portions of the sensor mounting rods and the water quality sensors of the tail ends of the sensor mounting rods through the waterproof quick connectors.