Fluorescence detection is widely used in biology and medicine, while the realization of on-chip fluorescence detection is vital for the portable and point-of-care test (POCT) application. In this letter, we propose an efficient fluorescence excitation and collection system using an integrated GaN chip consisting of a slot waveguide and a one-dimension photonic crystal (1D PC) waveguide. Slot waveguide is used to confine the excitation light for intense light-sample interaction and the one trip collection efficiency at the end of slot waveguide is up to 14.65%. More interestingly, due to the introduction of 1D PC waveguide, fluorescence signal is directly filtered out and the excitation light is reflected to the slot waveguide for multiple excitations. Its transmittances for the designed exciting wavelength of 520 nm and the fluorescent wavelength of 612 nm are 0.2% and 85.4%, respectively. Finally, based on numerical analysis, the total fluorescence collection efficiency in our system amounts to 15.93%. It is the first time that the concept of an all-in-one-chip fluorescent detection system has been proposed, which paves the way for on-chip fluorescent excitation and collection, and may find potential applications of miniaturized and portable devices for biomedical fluorescent detection.