Hydrogen sensor core, preparation method thereof and hydrogen sensor

The invention discloses a hydrogen sensor core, a preparation method thereof and a hydrogen sensor. The hydrogen sensor core comprises a semiconductor substrate, a source electrode, a drain electrode, a trench region, a dielectric layer, a hydrogen sensitive layer and a metal electrode layer which are arranged on the semiconductor substrate. The preparation method comprises the step of preparing the source electrode, the drain electrode, the trench region, the dielectric layer, the hydrogen sensitive layer and the metal electrode layer on the semiconductor substrate. The hydrogen sensor core has the advantages of being low in detection lower limit, high in sensitivity, short in response time and the like, the hydrogen sensor prepared from the hydrogen sensor core can detect the lower limit of hydrogen concentration which is very low and reaches 50 ppm, leakage of weak hydrogen can be found as soon as possible, and the effect of giving an alarm in advance is achieved; the response time is less than 60s, and th