I have been trying to using libcanard on stm32f103. there is a problem which I do not know which version about SPL should I choice . cause when I using SPL1.6 the function “RCC_ClocksTypeDef” is not right so could tell me which version is good to use?

Libcanard does not depend on any SPL version at all. SPL is used in the tutorials to make them more readable to avoid writing magic numbers to registers.
Also, RCC_ClocksTypeDef is not a function at all, it is data type intended to be used with function RCC_GetClocksFreq. But anyway, if for some reason this function does not work properly, you may just fill arguments of function canardSTM32ComputeCANTimings manually.