AbstractMultispectral imaging that captures multiple band information for effective environmental or object identification is of great interest in medical, vision, military, and space applications. Monolithic stacked detectors based on epitaxial electronics have been the principal option for infrared dual‐band imagers. However, the integration of these single‐band units would inevitably lead to performance reduction, high fabrication cost, and low reproducibility yield, which limits the widespread application of such technology. Here, a high‐throughput blade coating process is demonstrated to fabricate monolithic double‐perovskite‐layer photodiodes with preferential crystallographic morphology and high reproductivity. The device delivers electrically switchable dual‐band response with a dark current below 10−9 mA cm−2, a selective spectral response of 300–1100 nm, and bandwidths of 16.5/>20 MHz for two distinct bands. Furthermore, such device configuration can concurrently capture dual‐color spectral information under an AC‐driven mode, enabling the complementary dual‐spectral imaging for bioimaging and environmental monitoring.