The invention discloses an office table frame structure easy to demount and mount. The office table frame structure comprises two side frames which are symmetrically arranged, and the tops of the side frames are connected with cross beams of an office tabletop; the office table frame structure comprises connecting and fixing components, each connecting and fixing component comprises a connecting component and a fixing component, each connecting component and the corresponding fixing component are fixedly connected, and each connecting component comprises a first supporting portion and a second supporting portion which are integrally arranged and set up at the tops of the side frames; each fixing component comprises a fixing block and a slider, each fixing block is connected at one end of the corresponding connecting component, a fixing block opening is formed in the middle of each fixing block, a slope is arranged at the bottom of each fixing block opening, and each slider is arranged in the corresponding fixing block opening and slides along the corresponding slope; each connecting and fixing component further comprises a slider pushing mechanism which pushes the corresponding slider to move, and each cross beam comprises cross beam holes. By adopting the office table frame structure, the technical problem that demounting and mounting of office tables are time-consuming and troublesome in operation in the prior art can be solved.