For studying the hydration mechanism under temperature match curing， a series of experiments were carried out to investigate the degree of reaction of fly ash, pore structure and hydration products of the cement paste with high volume of fly ash at different curing age. Results indicate that compared with standard curing, the degree of reaction of fly ash and quantity of consumed alkali metal are higher under temperature match curing at early age, but the difference is lessened at late age. Also, pore structure of the cement paste with high volume of fly ash is optimized and hydration products are different in composition and morphology under temperature match curing, but the difference gradually disappears with long term hydration.