The invention relates to a conveyable light marine 90t workover rig, consisting of workover equipment modules with each weight controlled within 8t. Slide rails can be arranged according to distribution conditions of well head grooves of a series of marine oil-gas production platforms without a workover rig and flexibly installed and arranged. The workover rig can realize that the traditional spud legs satisfy well workover load requirements and workover operations of all oil-gas production platforms configured with a crane with the hoisting capacity of more than 10t and related well stimulation requirements, and has the advantages of reducing development costs of marginal oil fields at the same time and providing effective means for carrying out tapping potential measures of the similar simple production platforms and eliminating underground potential safety hazards. The workover rig has the characteristics of simple structure, short installation period, wide application, and the like.