Portable water quality rapid detection device has been widely used in water environment monitoring，and it plays an important role in the field of water quality pollutants detection in multiple scenes such as sudden environmental pollution events，watershed investigation and water quality process diagnosis. However，the current used portable water quality rapid detection device falls short of meeting the actual needs of on-site monitoring，necessitating the urgent development of novel technologies for expedited water quality assessment，and there is an urgent need to develop new technologies for water quality rapid detection. Leveraging spectrophotometry，this study devised a miniaturized，intelligent and portable water quality rapid detection device based on data intelligent transmission，along with its accompanying detection reagents. The actual size of the portable water quality rapid detection device was 240 mm × 92 mm × 51 mm，and the equipment weight is only 0.413 kg. It combined the advantages of volume and weight and could store more than 10 million detection data，greatly improving the portability and field practicality of the equipment. Following a thorough evaluation of the device's stability and verification through laboratory comparisons，results showed that the absorbance stability measured continuously within 20 minutes at a wavelength of 410-685 nm was 0-0.001 A，measured wavelength error was between -0.1 nm and 0.5 nm，wavelength repeatability was 0-0.5 nm. At the same time，the accompanying detection reagents of portable water quality rapid detection device had high chemical reaction activity，short reaction time and strong anti-interference ability by improving the reagent formula，which could effectively realize fast and accurate determination of various complex water quality such as black and smelly water，seawater and high hardness. Moreover，the digestion device demonstrated an average temperature deviation of -0.2 ℃ to -3.7 ℃ at 165 ℃. The relative standard deviation within the laboratory for each testing parameter was less than 5.0%，the relative standard deviation between laboratories was also less than 8.0%. Additionally，the recovery ranged from 89.7% to 108%. Results indicated that the detection limit，precision and accuracy of detection device align with standard requirement，ensuring its stability and reliability. Furthermore，intelligent data transmission-constructed monitoring terminal platform had facilitated in-depth analysis of nearly 200 000 measured data points，which ensured swift identification of irregularities in water treatment facility operations，assisting enterprises in implementing appropriate safeguards and realizing the transformation of rapid detection data from “monitoring” to “use”，from “loose” to “cluster”，thus transcending the limitations of traditional water quality rapid detectors in field applications.