The present invention relates to preparation process and ageing method of catalyst for direct oxidation and esterification of unsaturated aliphatic aldehyde to produce unsaturated carboxylic acid ester. The preparation process of the catalyst includes adding competitive adsorbent while loading the active component and assistant, microwave heating while loading and reducing the active component, high temperature calcining the loaded active component before reduction, and the ageing treatment of the prepared catalyst with ageing agent. Thus prepared catalyst has high performance, raised unsaturated aliphatic aldehyde converting rate and unsaturated carboxylic acid ester selectivity, relatively long service life and high reaction material utilizing rate.