DH5a and Top Ten have a slightly different genotype but both  are used for routine cloning purposes and plasmid propagation where they can be used pretty much interchangeably.

How many colonies did you get? I mean you only need one correct construct. But here are some suggestions:

1) PCR clean up: Make sure that you remove all of the wash buffer before applying the elution buffer. Check the concentration of the purified product by agarose gel.

2) Ligation: Double check concentrations of vector backbone and insert. Use different vector:insert ratios (1:2, 1:3, 1:5 etc). There are good web based tools that do the calculations for you.

What cloning method do you use? Restriction enzyme based or TA cloning?

Thank you for your advice. 

I use TA cloning and I had 2 colonies in one plate.

Here're two additional questions:

(1) how to know the efficiency of competent cell

If I need to check the efficiency of competent cell, should I put the vector without insert DNA into competent cell, then incubate overnight and count colonies?

(2) how to check ligation efficeincy

As your advice, different ratios of vector and insert would affect the ligation result. I'd like to check it by changing the ratio. Can I measure vector's concentrations by nano drop?

To estimate transformation efficiency you may use any vector (pUC, pTZ, Bluescript etc), but you need to dilute it 1000-10000 fold (0.1 ng/ul concentration looks most convenient). Efficiency is OK if 0.1 ng of a vector gives at least 100 colonies. You may inspect ligation by electrophoresis, but I never do this. Absence of colonies in case of good cells indicates problems with ligation.

Nano drop properly works only in case of very pure and good quality DNA. I always estimate DNA concentration by comparison of band intensities on ETBR gel. TA cloning requires equal molar concentrations (you should take in account fragment size) of vector and insert.