A secret image sharing with deep-steganography and two-stage authentication based on matrix encoding is proposed. This scheme firstly employed Wang and Su's sharing scheme to share a secret image into n shadows. Then, n shadows were embedded into the pre-selected cover images by using matrix encoding so as to generate n stego images. Different from the common schemes which directly use LSBs replacement, our scheme performs deepsteganography, which hides 3-bit secret data but only modifies at most 1-bit via matrix encoding. Benefiting from the comparatively slight modification to the cover image, our scheme obtains enhancement in both the security of secret data and the visual quality of the stego image. As far as the authentication ability is concerned, our scheme explores a two-stage authentication: the first uses a sub-key to pass identity authentication, and the second performs tamper authentication. The experimental results show that our scheme achieves better authentication ability than the referenced schemes.