Light therapies have been applied to millions of patients for treating many kinds of diseases, especially superficial ones. Currently, mainstream light therapies utilize the combined effects of photosensitizers and light to either remove disordered tissue or promote the growth of healthy tissue. Adverse effects of light therapy, including metabolic burden caused by circulatory photosensitizer and skin damage induced by high irradiance light, are yet to be addressed. This study provides a Miniaturized all-in-one Light therapy Device (MiLD). All components required for light therapy, including dual-function microneedles, LED array, control circuit, and battery are integrated together to form a miniaturized portable device with 2 cm in length, 1.7 cm in width, 1.2 cm in height, and 3.6 g in weight. The all-in-one design and patch-to-cure operation of MiLD enables the successful demonstration of point-of-care light therapy. Satisfactory therapeutic effects have been verified in mice on both types of light therapy. Meanwhile, transdermally co-delivering both photosensitizer and light in situ fully avoids photosensitizer accumulation in blood and remarkably reduces the irradiance of light, therefore significantly alleviating metabolic burden and light-induced skin damage. Overall, the MiLD lays the technical foundation of point-of-care light therapy with its miniaturized all-in-one design, simple patch-to-cure operation, satisfactory therapeutic effects, and minimum adverse effects.