The invention relates to an ionizing radiation measuring method and device based on an area array camera chip. The method comprises the steps that S1 ionizing radiation particles and radiation photons are captured by the area array camera chip, and are converted into digital signals; S2 the digital signals generated by the area array camera chip are processed, and ionizing radiation dose is output; and S3 the ionizing radiation dose is digitizedly or graphically displayed. According to the invention, the area array camera chip is used to detect ionizing radiation, which has the advantages of multi-channel detection and high data output efficiency; a high-voltage conversion circuit in the prior art is avoided; the device has the advantages of simple and reliable circuit and convenient use, and can detect single ionizing radiation particles or radiation photons; high-precision ionizing radiation dose detection can be realized in combination with a connected domain algorithm and a two-dimensional Gaussian distribution function; the ionizing radiation energy can be detected; and the ionizing radiation hazard level of the current scene can be inferred.