A multiplex slide plate device is provided, including a slide plate, a sacrificial layer, and a housing. The slide plate has reaction vessels arranged in an array. The sacrificial layer has a microfluidic channel, which has an injection channel, a main channel, and a distal channel connected to each other. The housing is used to accommodate the slide plate and the sacrificial layer, and is composed of a cover and a tray, and the cover has an injection hole, an exhaust hole, and a storage tank. A sample solution and an oil are injected from the injection hole into the injection channel, wherein the sample solution is pushed by the oil. The sample solution loads into each of the reaction vessels while flowing through the main channel. Excess waste liquid flows from the exhaust hole into the storage tank, and is covered by the oil and cannot reflow.