To handle the high heat load obtained by photon absorbers located in the front-end of Shanghai Synchrotron Radiation Facility (SSRF), the structure design and optimization of photon absorbers were researched. The dispersion strengthened copper called GlidCop AL-15 was used to manufacture the absorbers. Direct water cooling and grazing incidence structures were used to improve thermal controlled-release ability of the front-end photon absorbers. The Petukhov formula and Darcy-Weisbach formula were selected to optimize cooling water channels. After thermal analysis with ANSYS for the temperature and thermal stress distributions of photon absorbers with different structure parameters, the structure optimization parameters of photon absorbers were determined. It shows that the diameter of cooling channels is 6 mm, the distance of photon confining surfaces to cooling channel walls is 9 mm, corner radiuses of two adjacent photon confining surfaces are bigger than 2 mm and the directions of cooling channels are parallel to the beam approximately. As compared to the original ones, the maximum temperatures of the photon absorbers and their cooling channel walls have declined by 8% and 1/4 respectively, the maximum equivalent stresse is only by half of the original ones. These results entirely satisfy the design requirements of SSRF front-end.