It is such a great project. Must have taken a long time!

I am really new!!

I had one request: can you post a simple version of this control circuit code? May be  in TX: one joystick. And in Rx a servo and motor. If possible may be one temperature sensor in the RX station which is shown in LCD screen at TX station. 

https://github.com/buk7456/Arduino-RC-basic-transmitter

It is a very basic 6 channel version that works well. No screen or other fancy features.

It's so great. How about the stability of the connection?. I made RF remote control using nrf24l01, however it lost the signal frequently. Thus my drone always fall down while flying . Can the LORA sx1278 improve this matter?

The connection is stable enough. Tested the link up to 2km away Line of sight  and didnt experience any connection problems at this distance. Of course your range may vary depending on how noisy your environment is.

The code can be run.But, The main mcu code does not extend to flash memory on Uno. Sketch code size was 35kb.  Please advise. Mr.

It compiles fine with Arduino IDE 1.8.9 and later. Sketch uses 29980 bytes enough to fit in Arduino Uno flash with extra flash to spare.

how the transmitter code loaded to the two atmega328 

how to connect atmega328 with lora, the schematic image can't i understand it.

I have updated the schematics. Hope they are now more understandable