Superconducting kinetic inductance detectors (KIDs), featuring low noise, high sensitivity, singlephoton energy resolution, and easy scalability to large-format arrays, have been widely studied and preliminarily applied in astronomical detection. This paper designs, fabricates, and characterizes a 20008- pixel superconducting KID array for the optical and near-infrared wavelength band. The array contains 10 readout lines with approximately 2000 pixels per line. The pixels are arranged in a circular area with a diameterof 24 mm, and the overall array size is 32 mm×50 mm. The pixel spatial layout is optimized by simulating the frequency shift as a function of pixel spacing in different directions. It is found that a pixel pitch of 150 μm can reduce the inter-pixel frequency crosstalk below 220 kHz, ensuring the integrity and stability of signal readout for the high-density KID array. By designing and optimizing the impedance transformation network, the simulated reflection coeffcient S₁₁ can be reduced to below -11 dB, enabling effcient signal transmission between the array and the readout circuit. In addition, a microlens array is designed with a focused light spot of diameter below 40 μm, matching the inductive absorber area of 39 μm×39 μm, to improve the optical absorption effciency. 100 nm thick high-resistivity hafnium (Hf) film with low superconducting transition temperature (T_C ≈ 350 mK) is preliminarily fabricated using DC magnetron sputtering, and serves as the superconducting film for the KID array. The microwave transmission S₂₁ of the Hf KID array is measured at a base temperature 20 mK, showing internal quality factor (Q_i) ranging from 3×10³ to 80×10³ and higher resonance frequencies than designed values. We discuss the factors that may lead to the decrease in Q_i and the resonance frequency away from designed value. These results demonstrate the potential feasibility of high-density KID arrays with number of pixels on the order of 104 for the optical and near-infrared wavelength band.