In view of insufficient security in the next generation passive optical network, an electro-optic hybrid encryption scheme based on MD5 message digest algorithm check is proposed in this paper. In the scheme, Baker scrambling algorithm and 256 bit Advanced Encryption Standard (AES) encryption algorithm are used to encrypt the picture data. The Low Density Parity Check Code (LDPC) error correction and MD5 check are combined to perform the error correcting coding and check the consistency of the encrypted picture data. In order to strengthen the security of key and MD5 digest distribution, Super Structure Fiber Bragg Grating (SSFBG) is also used to encode them so that they are hidden under the system noise. The simulation results show that after SSFBG coding, the power of the coded signal is as low as-50 dBm, which can achieve the effect of data hidden transmission over the optical fiber channel. Due to the fact that the MD5 check of the received data is added in the scheme, the information changes caused by malicious access attacks cannot be decoded by AES, which improves the security and saves Central Processing Unit (CPU) resources at the same time. Finally, Error rate curve analysis results show that the receiver sensitivity can be effectively reduced by adding LDPC error correction.