A femoto-streak image tube has been designed,in which a static electrode was used as the focus lens. The distribution of the initial kinetic energy,the initial azimuth angle,elevation angle and position of the photoelectrons were sampled with Monte Carlo method. The spatial electric field strength was calculated with Finite Difference method,and the trajectories of 3000 photoelectrons were calculated with fourth Runge-Kutta method. After analysis the spatial and temporal distribution of the electrons on the optimum plane,the basic character parameters such as the spatial transfer function and temporal resolution et al of the image tube were provided,the total temporal resolution of the image tube was expected to reach to 290.4 fs.