CuAlO2 thin films have extensive applications in optoelectronic devices such as solar cell, liquid crystal display, heat mirrors and many others different applications, this material were prepared by different deposition method. In this work spray pyrolysis technique was used to prepared CuAlO2 thin film deposited on n-type silicon with (10 Ωcm) resistivity and (100) orientation. The solution was mixture of copper chloride (CuCl2.2H2O) and aluminum chloride (Al2Cl3.2H2O) salts with different concentration (1:1), (1:2), and (2:1) of (Cu: Al) ratio. It has been found that the concentration of (1:1) is the best and selected to be the ratio used to prepare thin film for studying the effect of laser annealing on the optical, structural, electrical and optoelectronic properties. Laser annealing has been done at different energy fluence (300, 600, 900 and 1200) mJ/cm2. X-ray diffraction analysis has confirmed the formation of delafossite phase of (CuAlO2) and increased its intensity at annealing energy fluence (300, 600) mJ/cm2. The morphology of CuAlO2 was obtained by using AFM, which referred that the films were homogeneity and its grain size , roughness and rms affected by laser annealing energy fluence. The optical characteristics of CuAlO2 thin films have been investigated such as transmittance, absorption coefficient, energy gap, and extinction coefficient. The transmittance was calculated from(200 to 1100 nm), and it reached to 74% at (300 mJ/cm2) annealing energy fluence. The direct and indirect band gap were varied according to annealing energy fluence in range of (3.4 to 3.1) eV and (2.1 to 1.5) eV respectively. The electrical measurement showed the resistivity of the film reduced with rising temperature and laser energy fluence which reflected positively on the conductivity of thin films whereas the highest conductivity was ( 24.2 (Ω.cm)-1) at (600 mJ/cm2), the measured activation energy decreased with increasing of energy fluence. I-V and C-V characteristic were studies and the ideality factor (n) was 2.9 at (1200 mJ/cm2), while the built-in-potential (Vbi) decreased by annealing energy fluence. The maximum responsivity obtained were (2.86) A/W at 825 nm with (300 mJ/cm2) was measured.