Upconversion is a phenomenon that converts low-energy photons into high-energy photons. It has a wide range of potential applications in three-dimensional fluorescence microscopy, solar cells, photocatalysis and other fields, and thus has become an attractting topic in the field of organic fluorescent materials. At present, the research about organic low light upconversion materials based on the triplet-triplet annihilation (TTA) mechanism has been investigated in much more depth, and there have been many reesearch reports discussing the TTA mechanism and application; while the research discussing on the other organic upconversion mechanism, the one-photon hot band absorption upconversion (OPA-UC), is still relatively rare. Azaanthracene derivatives are ideal model molecular structures for studying TTA-UC and OPA-UC organic upconversion luminescence due to their good structural rigidity, planarity, and high fluorescence quantum yield. This work compares three azaanthracene derivatives: Phenosafranine (PSF), Safranine T (Safranine T, SFT), Methylene Violet (MTV) and their respective TTA-UC and OPA-UC difference in luminescence performance, analyze and explore the structure-activity relationship of molecular structure to OPA-UC luminescence performance and TTA-UC sensitization efficiency. Experiments have found that phensafranine and safranine T had higher fluorescence quantum yields and a larger radiation attenuation constant. The main attenuation process was radiation attenuation, while methylene violet had a higher intramolecular charge transferability (Intramolecular charge transfer, ICT), so the non-radiation attenuation part was more. It was found that the triplet energy level of methylene violet was too low to carry out the triplet-triplet energy transfer process, and safranine T had a higher triplet lifetime due to its higher triplet lifetime. The upconversion luminous efficiency (9.69%) was 3 times (3.16%) of the phensafranine system. Further studying the OPA-UC performance difference between phensafranine and methylene violet and found that the OPA-UC luminous efficiency of methylene violet (0.12%) under the same concentration condition (10^-3 mol·L^-1) was much higher compared with that of phensafranine (0.059%) and as the concentration increased, the OPA-UC luminescence enhancement effect of methylene violet was greater. Further results showed that in the TTA-UC luminescence process, the sensitization efficiency of the photosensitizer was mainly affected by the molecular triplet lifetime and the inter-system inter-system transitioning ability. The longer the lifetime, the stronger the inter-system inter-system transitioning ability and the higher the sensitization efficiency; In the OPA-UC luminescence process, the luminescence efficiency of the luminescent agent molecules were mainly affected by ICT. The greater the ICT degree, the higher the molecular luminescence efficiency. In this work, azaanthracene molecules have a low cost and are easy to obtain, which has certain practical significance for designing high-performance TTA-UC and OPA-UC luminescent molecules in the future.