针对空间相机内部隔热板起到隔离入射太阳光影响相机内部光学结构的作用，其厚度较小，一般不采用额外的散热措施，入射太阳光能量作用其上会引起较大的温升，温度增加的不均匀会增加相机内部的红外杂散辐射，提出一套完整的隔热板厚度优化方法。在保证隔热板体积不变的前提下，利用仿生优化原理，根据隔热板各处的温度梯度差异调整隔热板的厚度。对优化出的隔热板厚度函数进行高斯滤波处理，使隔热板的厚度变化均匀，便于加工。通过对比优化前后的温度场与红外场，发现优化后最高温度降低了3.8℃，其3 μm ~5 μm，8 μm~12 μm波段的红外辐出度降低了15%，该优化方法可以作为内部杂散辐射的抑制手段与其他方法一起实施。

The thermal insulating board inside the space camera acts as a role of insulating the internal optic structure from the sunlight radiation which can cause a sharp temperature rise of the board, since it is usually thin and does not add extra cooling components. The difference of increased temperatures on the insulating board can increase interior infrared stray radiance. A full set of thickness optimization method for thermal insulating board was presented. Using the mechanism of bionic optimization, the thickness of the insulating board was optimized according to the temperature gradient difference along the board while keeping the total volume unchanged. Then the Gauss filtering was conducted to make the thickness of insulating board change smoothly and easily for manufacturing. Through comparing the temperature profile and infrared radiance before and after optimization, the result showed that the highest temperature reduced by 3.8℃, and the infrared radiance at the wavelength of 3 μm~5 μm and 8 μm~12 μm reduced by 15%. The optimized method could be used to reduce the interior stray radiance by combining with other methods.