The invention discloses detecting equipment and method for online sealing property of a thin-film capacitor. The detecting equipment for the online sealing property of the thin-film capacitor comprises a sealing container, a testing and detecting component and a sorting component, wherein the sealing container is provided with a closed cavity for containing a detected capacitor; the testing and detecting component is connected with the sealing container and can be used for filling the sealing container with fluid with a set pressure and detecting a pressure change value of fluid in the sealing container in real time; and the sorting component can be used for sorting a bad capacitor and/or a good capacitor according to the pressure change value of the fluid in the sealing container. By applying the technical scheme provided by the invention, the testing and detecting component is arranged for detecting whether the detected capacitor leaks or not according to the pressure change of the fluid, and improving the detecting efficiency of the detected capacitor, thereby achieving the aim of improving the production efficiency; and the sorting component is arranged and can be used for identifying the bad capacitor according to the pressure change value of the fluid and digitalizing the sealing property identification of the capacitor.